Appendix:Dictionary of Mining, Mineral, and Related Terms/P/7

psammite
 * a. A sandstone. The term is equivalent to the Latin-derived term arenite.

b. A term formerly used in Europe for a fine-grained, fissile, clayey sandstone. c. The metamorphic derivative of arenite. Etymol: Greek psammos, sand. See also: psephite; pelite. Adj. psammitic.

psatyrite
 * See: hartite.

psephite
 * a. A sediment or sedimentary rock composed of large fragments set in a matrix varying in kind and amount; e.g., talus, breccia, shingle, gravel, and esp. conglomerate. The term is equivalent to the Latin-derived term rudite.

b. The metamorphic derivative of rudite. Etymol: Greek psephos, pebble. See also: psammite; pelite. Adj: psephitic.

pseudo-
 * A prefix meaning false or spurious.

pseudoanticline
 * An upward buckling of the superficial layers of the ground due either to changes in volume brought about by pedogenic processes or to some other nontectonic cause.

pseudoboleite
 * A tetragonal mineral, Pb (sub 5) Cu (sub 4) Cl (sub 10) (OH) (sub 8) .2H (sub 2) O ; indigo blue; occurs only in parallel growth on boleite, at Boleo, Baja California, Mex. Also spelled pseudoboleite.

pseudobreccia
 * A partially dolomitized limestone, characterized by: a mottled appearance, that gives the rock a texture mimicking that of a breccia; or by a weathered surface that appears fragmental. It is produced diagenetically by selective grain growth in which localized, patchy, and irregularly shaped recrystallized masses of coarse calcite are embedded in a lighter colored and less altered matrix of calcareous mud.

pseudobrookite
 * An orthorhombic mineral, Fe (sub 2) (Ti,Fe)O (sub 5) ; resembles brookite; occurs in cavities in andesites. See: brookite.

pseudochromatism
 * Colors and color plays produced by physical optics as opposed to chromophores; e.g., diffraction, dispersion, and scattering. Syn: structural color. CF: play of color.

pseudoconglomerate
 * A rock that resembles, or may easily be mistaken for, a normal sedimentary conglomerate. Examples include a crush conglomerate consisting of cemented fragments that have been rolled and rounded nearly in place by orogenic forces; a pebble dike; a sandstone packed with rounded concretions; and an aggregate of rounded boulders produced in place by spheroidal weathering and surrounded by clayey material. See also: crush conglomerate.

pseudocrocidolite
 * Quartz pseudomorphous after crocidolite. Syn: tiger's-eye; hawk's-eye.

pseudocrystalline
 * Composed of detrital crystalline grains little worn and solidly compacted by siliceous or other mineral matrix, so as to resemble a true crystalline rock.

pseudoeutectic texture
 * Intergrowth of sulfide minerals that simulate eutectic texture in metals. See also: graphic granite.

pseudofibrous peat
 * Peat that in spite of its fibrous condition, is soft, noncoherent, plastic, and on drying, shows great shrinkage. See also: fibrous peat; amorphous peat.

pseudogalena
 * See: sphalerite.

pseudohexagonal
 * Descriptive of minerals with hexagonal habit without hexagonal symmetry; e.g., hexagonal plates of monoclinic mica.

pseudojade
 * A name that may be applied to any mineral resembling jade in appearance; e.g., bowenite, massive serpentine.

pseudoleucite
 * Large isometric crystals consisting of mixtures of nepheline and orthoclase, or of analcime formed as breakdown products of leucite; occurs in syenites from Arkansas, Montana, and Brazil. CF: leucite; metaleucite.

pseudomalachite
 * A monoclinic mineral, Cu (sub 5) (PO (sub 4) ) (sub 2) (OH) (sub 4) ; trimorphous with ludjibaite and reichenbachite; dark green. Syn: dihydrite; phosphochalcite; phosphorochalcite; tagilite.

pseudomorph
 * A mineral sample with the external crystal form of one mineral and the internal chemistry of another; e.g., cubes of geothite after pyrite resulting from oxidation of the ferrous sulfide to ferric oxyhydroxide. CF: paramorph. Syn: false form; allomorph.

pseudomorphous quartz
 * Quartz displaying the form and habit of any of several mineral species, which it has assumed through replacement. The most common quartz pseudomorphs are those of calcite, barite, fluorite, and siderite. Silicified wood is quartz pseudomorphous after wood.

pseudomorphous tonstein
 * A type of tonstein characterized by numerous pseudomorphs of kaolinite-feldspar or kaolinite-mica within a kaolinite groundmass.

pseudophenocryst
 * See: porphyroblast.

pseudophite
 * A compact massive mixture of chlorite minerals resembling serpentine.

pseudoporphyritic
 * a. Said of the texture of an igneous rock in which larger crystals have developed in a macrocrystalline groundmass, but were formed, at least in part, after the rock solidified (e.g., large potassium-feldspar crystals in a granite).

b. See: porphyroblastic.

pseudosecondary inclusion
 * A fluid inclusion formed by healing of a fracture occurring during growth of the host crystal.

pseudosuccinite
 * Variety of amber differing from Baltic amber in its reaction to solvents.

pseudosymmetrical
 * Said of crystal structures in which the atoms are only slightly displaced from positions that would be in accord with a higher symmetry. Thus, a monoclinic, pseudotetragonal mineral contains atoms only slightly displaced from positions of tetragonal symmetry.

pseudosymmetry
 * a. Close angular approximation of a mineral with lower symmetry to one of higher symmetry; e.g., pseudohexagonal micas with monoclinic symmetry.

b. Compound twins simulating an external symmetry not found in their atomic structure; e.g., orthorhombic aragonite in pseudohexagonal prisms. Syn: mimetic. c. Abnormal crystal growth along one direction; e.g., elongate native gold cubes with apparent tetragonal symmetry.

pseudotachylyte
 * a. A dense rock produced in the compression and shear associated with intense fault movements, involving extreme mylonitization and/or partial melting. Similar rocks, such as some of the Sudbury breccias, contain shock-metamorphic effects and may be injection breccias emplaced in fractures formed during meteoric impact. CF: ultramylonite.

b. A dark gray or black rock that externally resembles tachylyte and that typically occurs in irregularly branching veins. The material carries fragmental clasts of adjacent rock units, and shows evidence of having been at high temperature. Miarolitic and spherulitic crystallization has sometimes taken place in the extremely dense devitrified base. Some pseudotachylyte has behaved like an intrusive and has no structures obviously related to local crushing.

pseudotopaz
 * Quartz simulating topaz. From Striegau, Silesia, Poland.

pseudoviscosity
 * Viscous resistance offered by a slurry, sludge, mud, or suspension of minerals in water as a pulp, due to the specific surface involved, with possibly an element of thixotropy under stated conditions of pH value, agitation, flow, temperature, and solid-to-liquid ratio. The pseudoviscous effect is distinct from viscosity due to molecular shear.

pseudovolcano
 * A large crater or circular hollow believed not to be associated with volcanic activity; e.g., a crater that is possibly meteoritic in origin but may be the result of phreatic explosion or cauldron subsidence. Adj: pseudovolcanic.

pseudowollastonite
 * Synthetic triclinic CaSiO (sub 3) polymorphous with wollastonite-1T, wollastonite-2M, and wollastonite-7T.

psilomelane
 * a. A general term for massive oxides of manganese not otherwise identified; commonly botryoidal or colloform; a source of manganese in the United States (Arkansas, Virginia, Georgia); also in India, South Africa, and Russia. CF: cryptomelane; wad.

b. See: romanechite; manganese oxide. CF: pyrolusite.

psilomelanite
 * See: psilomelane.

psychrometer
 * An instrument for measuring the vapor pressure and the relative humidity of the air or the quantity of moisture in the air. It consists of a dry-bulb thermometer and a wet-bulb thermometer, the latter having its bulb covered with a layer of muslin kept moist with water. The rate of evaporation from the moist muslin depends upon the quantity of moisture in the air. The more rapid the evaporation, the greater the cooling, and hence the greater the difference in the temperature readings of the two thermometers. Also called: hygrometer.

psychrometry
 * a. Study of atmospheric humidity and its effect on workers. The psychrometer, or hygrometer, measures the difference between dry-bulb and wet-bulb thermometer readings.

b. The determination of the psychrometric properties of air at a given state point. c. Measurement of the humidity of air.

pteropod ooze
 * A fine-grained pelagic deposit with more than 30% calcium carbonate of organic origin, of which pteropods are an important constituent.

ptilolite
 * See: mordenite.

ptygmatic
 * See: ptygmatic folding.

ptygmatic folding
 * Primary folding in migmatites (injection gneisses, etc.), caused by the high-temperature and high-pressure processes to which the migmatites owe their origin and composite character. CF: flow folding.

public domain
 * Land owned, controlled, or heretofore disposed of by the U.S. Government. It includes the land that was ceded to the Government by the original 13 States, together with certain subsequent additions acquired by cession, treaty, and purchase. At its greatest extent, the public domain occupied more than 1,820 million acres (737 million ha). See also: public land.

public land
 * Land owned by a government, esp. a national government; specif. the part of the U.S. public domain to which title is still vested in the Federal Government and that is subject to appropriation, sale, or disposal under the general laws.

public land and public use
 * There is a clear distinction between public lands and lands that have been severed from the public domain and reserved from sale or other disposition under general laws. Such reservation severs the land from the mass of the public domain and appropriates it to a public use.

public limited liability company
 * An association of individuals, at least seven in number, who together subscribe the necessary means or capital--i.e., money, property, or other credit--to engage in a joint undertaking.

public mineral land
 * Land belonging to the United States containing a deposit of mineral in some form, metalliferous or nonmetalliferous, in quantity and quality sufficient to justify expenditures in the effort to extract it and subject to occupation and purchase under the mining laws.

pucherite
 * An orthorhombic mineral, BiVO (sub 4) ; trimorphous with clinobisvanite and dreyerite; reddish brown; a source of vanadium.

pucking cutter
 * A worker employed in a coal mine to cut the floor in cases of creep or upheaval toward the roof.

puddingstone
 * a. A siliceous rock cut into blocks for furnace linings.

b. See: conglomerate.

puddle
 * a. Earthy material--such as a mixture of clay, sand, and gravel--placed with water to form a compact mass to reduce percolation.

b. To place such material. c. To compact loose soil by soaking it and allowing it to dry. d. The molten portion of a weld. e. To work (metal) while molten. f. To subject (iron) to the process of puddling.

puddled steel
 * Steel made in a puddling furnace, a type of reverberatory furnace in which the flame plays down upon the metal.

puddler
 * a. Worker who converts cast iron into wrought iron by puddling. See also: puddling.

b. A rabble used in puddling. c. A puddling furnace. d. A system of small pipes admitting compressed air to a tank of water and zinc chloride, to effect a thorough solution for use as a timber preservative. e. A machine for breaking up alluvial wash, consisting of a shallow tank in which the arms rotate slowly. The coarse stones are forked out and the pulp passed down sluice boxes along which the gold settles. See also: tormentor.

puddle roll
 * Any of the roughing rolls through which puddle balls are passed to be converted into bars. Collectively called a puddle train.

puddling
 * The agitation of a bath of molten pig iron by hand or by mechanical means, in an oxidizing atmosphere, in order to oxidize most of the carbon, silicon, and manganese, and thus produce wrought iron. See also: danks' puddler.

puddling furnace
 * A reverberatory furnace for puddling pig iron.

puddling machine
 * A machine used for mixing auriferous clays with water to the proper consistency for the separation of the ore.

puff blowing
 * Production of wrought iron from molten pig iron, in an oxidizing atmosphere in a reverberatory furnace of special design. IL  :�d ��d �����       � s DICTIONARY TERMS:puff blowing Blowing chips out of a hole by means o Blowing chips out of a hole by means of exhaust air from the drill.

puffed bar
 * In powder metallurgy, a cored bar expanded by internal gas pressure.

puffer boy
 * A person employed to operate an engine used for hauling loaded mine cars through haulageways. Also the operator of any small stationary hoisting engine. See also: puffer man.

puffer man
 * In bituminous coal mining, a worker who operates a small hoisting engine used for hauling loaded mine cars through haulageways in a mine, or operates a small stationary engine used for hoisting coal or rock in a shallow shaft, esp. for prospecting or development work. Also called: puffer; puffer boy; puffer tender.

puffer tender
 * See: puffer man.

puffstone
 * Eng. Travertine; hard enough to use for building; so called from its cavernous structure.

pug
 * a. A parting of clay that sometimes occurs between the walls of a vein and the country rock; gouge.

b. The coal left on the floor by a coal cutter. See also: following dirt. c. Clay or other material used in packing cracks to prevent leakage; also, to use this material. d. Crushed strata or clay. See also: flucan.

pug lifter
 * One who removes coal left adhering to the floor by a coal-cutting machine.

pug lifting
 * The breaking and clearing of the coal left adhering to the floor by a longwall coal cutter.

pug mill
 * a. A machine for mixing water and clay, consisting of a long horizontal barrel containing a long longitudinal shaft fitted with knives; the knives slice through the clay, mixing it with water, which is added by sprays from the top. The knives are canted to give some screw action, forcing the clay along the barrel and out one end.

b. See: paddle-type mixing conveyor.

pug-mill operator
 * a. One who prepares ground, sifted, and filtered clay for molding by mixing it with water in a rotary-type mixer called a pug mill. This machine is frequently operated in conjunction with an auger mill and a cutting machine, the same worker tending the operation of all three machines simultaneously. Also called clay pugger; mixing-mill operator.

b. One who mixes ground preheated magnesia and carbon with hot asphalt in a pug mill to form a viscous mixture suitable for processing into pellets. Also called: mixer tender; pug miller; pug-mill tender.

pug tub
 * See: settler.

pull
 * a. The unit advance during the firing of each complete round of shotholes in a tunnel.

b. To loosen the rock around the bottom of a hole by blasting. Usually used with a negative to describe a blast that did not shatter rock to the desired depth. c. The amount of core obtained each time a core barrel is removed from a borehole. d. To draw or remove coal pillars, or pillars of ore. e. To hoist drill-stem equipment from a borehole. f. Strata movements over large excavated areas will extend to the surface and the disturbed surface area is almost always larger than the area of the underground excavation. The extent of this pull or draw depends on the depth of the workings, the nature of the strata, the thickness of the seam being mined, and the degree of packing support. See also: draw.

pull-apart structure
 * Features produced in beds that have been disrupted and separated during soft-sediment deformation. See also: boudinage.

pull drift
 * A small crosscut through barren ground to connect two orebodies.

puller-out
 * An operator who charges, pulls out, and otherwise manipulates crucibles.

puller rod
 * The rod used between the crank arm or drive arm of the drive unit and the panline of a shaker conveyor. Also called: connecting rod.

pulley
 * a. A cylinder, with a shaft for mounting it so that it may rotate; used to change the direction or plane of belt travel. If the shaft is designed to be mounted so that it will not rotate, a pulley includes the bearings that provide for rotation of the cylinder on the shaft.

b. A sheave or wheel with a grooved rim, over which a winding rope passes at the top of a headframe. c. A wheel that carries a cable or belt on part of its surface.

pulley man
 * See: rollerman.

pulley oiler
 * In bituminous coal mining, a laborer who oils and greases the pulleys on which run the cables that are used to raise and lower cars along haulage roads underground and at the surface of mines.

pulley repairman
 * See: rollerman.

pull hole
 * In sublevel stoping, term applied to a raise along the haulage level put up to the first sublevel. The raise is enlarged at the bottom into a grizzly chamber immediately over the haulage level and at the top is widened into a funnel-shaped opening. As ore is broken, it drops directly into a pull hole.

pulling pillars
 * The common expression used for mining the coal in the pillars of a mine; robbing pillars. See also: pulling stumps.

pulling stumps
 * The process of taking out the pillars of a coal mine. See also: pulling pillars.

pull-over mill
 * A two-high mill in which a piece is rolled in one direction only, and after traveling between the rolls has to be passed back over the top roll for rerolling.

pull pin
 * A device for throwing mechanical parts in or out of gear, or for readily shifting in or away from a fixed relative position.

pull rope
 * The rope that pulls a journey of loaded cars on a haulage plane; the rope that pulls the loaded scoop or bucket in a scraper loader layout. See also: tail rope. Syn: main rope.

pull shovel
 * A shovel with a hinge- and stick-mounted bucket that digs while being pulled inward.

pullway
 * The path from the face to the loading point taken by the scraper of a scraper loading unit.

pull wheel
 * A large driving wheel or sprocket.

pulmonary dust
 * Dust harmful to the respiratory system, including: silica (quartz, chert); silicates (asbestos, talc, mica, sillimanite); metal fumes (nearly all); beryllium ore; tin ore; iron ores (some); carborundum; coal (anthracite, bituminous). Syn: fibrogenic dust.

pulp
 * a. A mixture of ground ore and water capable of flowing through suitably graded channels as a fluid. Its dilution or consistency is specified either as solid-liquid ratio (by weight) or as a percentage of solids (by weight).

b. Pac. Pulverized ore or coal mixed with water; also applied to dry, crushed ore. See also: vacuum filter.

pulp assay
 * Pac. The assay of samples taken from the pulp after or during crushing.

pulp balance
 * Balance that weighs ore or coal pulp in a container of known volume; graduated to show pulp density directly.

pulp climate
 * In mineral processing, the general physical and chemical conditions of a pulp, in which the pH, added chemicals, solid-liquid ratio, temperature, particle size range, and ionization of a flotation pulp are held within controlled limits while a considerable number of associated factors of less direct importance to the surface chemistry of the process are, at best, only indirectly monitored.

pulp density
 * a. In mineral processing, the amount of solids in a pulp, typically ranging from 10% to 25%, by weight. It has a marked effect on the recovery and grade of concentrate.

b. The weight of a unit volume of pulp; e.g., if 1 cm (super 3) of pulp weighs 2.4 g, then the pulp density is 2.4 g/cm (super 3).

pulp dilution
 * The ratio of water to solids by weight. It is expressed as a ratio; e.g., a pulp dilution of 3 to 1 means that a pulp contains 3 t of water for each ton of solids.

pulpit
 * The special platform upon which the operator of a Bessemer converter stands.

pulpit man
 * Person who operates the complex controls of a rolling mill, in which iron and steel ingots or billets are rolled into shapes such as bars, T's, rails, and sheets, by throwing the correct electric switches when signaled or by personal observation. Also called: manipulator operator; mill control operator.

pulpstone
 * A very large grindstone employed in pulp mills for crushing or grinding wood into fiber.

pulsator
 * a. A motor-driven air compressor that supplies compressed air to an electric channeler. It receives the exhaust from the channeling machine cylinder and thus utilizes the pressure of the exhaust.

b. In mineral processing, a Harz-type jig. See also: Harz jig.

pulsator jig
 * A gravity concentrator utilizing vertical pulsations in a hydraulic medium to separate particles by specific gravity differences.

pulsed infusion
 * A variation of water infusion that has been effective in reducing both explosives consumption and airborne dust concentrations during mining. Water is introduced under pressure into long holes containing explosive charges and forced into the coal seam by detonation of the charges. See also: infusion shot firing.

pulsed infusion shot firing
 * A coal blasting technique that consists of firing an explosive charge in a borehole filled with water under pressure. The water is introduced through an infusion tube that also seals the hole. When the charge is fired, it produces in the water a high-pressure impulse that is transmitted into the numerous water-filled cleavage planes and slips and thus breaks the coal. The energy from the explosive is used more efficiently than when blasting in the conventional manner, and better coal preparation is obtained. See also: water infusion; long-hole infusion.

pulsion stroke
 * In mineral concentration by jigging, the stroke of the plunger device that controls the hydraulic lift of water through the bed of particles.

pulsometer
 * a. A steam pump in which an automatic ball valve (the only moving part) admits steam alternately to a pair of chambers, forcing out water that had been sucked in by condensation of the steam after the previous stroke. It can tolerate very dirty water and has been widely used for shaft sinking and miscellaneous pumping duties.

b. A displacement pump with valves for raising water by steam, partly by atmospheric pressure, and partly by the direct action of the steam on the water, without intervention of a piston. Also called: vacuum pump.

pulsometer pump
 * Pump with two chambers that are alternately filled and discharged. An automatic ball valve admits steam, which forces out the charge from the filled chamber while the other is filling as its steam condenses.

pulverization
 * a. In soil stabilization work, the separation of particles from each other rather than the breaking up of individual particles. Separation of the particles is the first step towards good dispersion of stabilization additives and moisture.

b. The reduction of metal to fine powder by mechanical means. Syn: comminution; soil stabilization.

pulverize
 * To reduce (as by crushing or grinding) to very small particles (as in fine powder or dust).

pulverized fuel
 * Finely ground coal or other combustible material, that can be burned as it issues from a suitable nozzle, through which it is blown by compressed air.

pulverizer
 * See: fine grinder.

pulverulent
 * That which may easily be reduced to powder. Said of certain ores.

pumice
 * A light-colored, vesicular, glassy rock commonly having the composition of rhyolite. It is often sufficiently buoyant to float on water and is economically useful as a lightweight aggregate and as an abrasive. The adjectival form, pumiceous, is usually applied to pyroclastic ejecta. CF: scoria; pumicite.

pumiceous
 * Adj. form of pumice.

pumicite
 * A very finely divided volcanic ash or volcanic dust ranging in color from white to gray and buff. It is the unconsolidated equivalent of tuff. See also: ash. CF: pumice.

pump
 * A mechanical device for transferring either liquids or gases from one place to another, or for compressing or attenuating gases.

pump bob
 * The balance weight used to bring up the plunger in a Cornish pumping engine.

pump chamber
 * An underground pumping station.

pumpellyite
 * a. A monoclinic mineral, Ca (sub 2) (Mg,Fe,Mn)(Al,Mn,Fe) (sub 2) (SiO (sub 4) )(Si (sub 2) O (sub 7) )(OH) (sub 2) .H (sub 2) O ; pumpellyite group; individual species named according to the preponderance of Fe, Mg, or Mn; occurs in minute bluish-green fibers or plates in Michigan, California, Haiti, and New Zealand.

b. The mineral group jugoldite-(Fe), okhotskite, pumpellyite-(Fe), pumpellyite-(Mg), pumpellyite-(Mn), and shuiskite. Syn: Lake Superior greenstone.

Pumpelly's rule
 * The generalization, made by Pumpelly in 1894, that the axes and axial surfaces of minor folds of an area are congruent with those of the major fold structures of the same phase of deformation.

pumper
 * In bituminous coal mining, a person who works a hand pump to force water, accumulated underground in low places, into a drainage ditch flowing to a natural outlet or pumping station. See also: ram operator.

pump fist
 * Eng. The lower end of a plunger case of a pump.

pumping
 * a. The act of moving a liquid or gas by means of a pump.

b. The operation of filling a sludge pump by an up-and-down motion of the rods or rope. Also called pumping the sludger. c. In scraper operation, raising and lowering the bowl rapidly to force a larger load into it. d. Alternately raising and lowering a digging edge to increase the volume of dirt being transported. e. The motion of mercury in a barometer arising from the movement of a ship or from fluctuations of air pressure in a varying wind.

pumping engineer
 * In mining and in the quarry industry, a person who operates one or a battery of pumps to force excess water from a lower level to the surface or to a drainage tunnel. Also called: pitwright; plugman.

pumping head
 * In an airlift, the distance from the surface to the level of the water during pumping; it equals static head plus drop.

pumping shaft
 * The shaft containing the pumping machinery of a mine.

pump kettle
 * A convex perforated diaphragm fixed at the bottom of a pump tube to prevent the entrance of foreign matter; a strainer.

pump lift
 * a. The vertical distance that a pump can suck up water. Theoretically, this should be about 34 ft (10.4 m) at sea level; practically, the limit is about 26 ft (7.9 m).

b. The vertical distance a pump can force water to flow.

pump load
 * The back pressure and/or resistance to flow of fluids that a pump must overcome to force a fluid to flow through a pipeline, drill string, etc.

pump pressure
 * The force per unit area or pressure against which a pump acts to force a fluid to flow through a pipeline, drill string, etc.; also, the pressure imposed on the fluid ejected from a pump.

pump rod
 * The rod or system of rods (usually heavy beams) connecting a steam engine at the surface or at a higher level with the pump piston below. See also: balance bob. Syn: main rod.

pump-rod plates
 * Scot. Spear plates; strips or plates of iron bolted to wooden pump rods at the joints for the purpose of making the connection.

pump slip
 * Leakage past the valves and the plunger in a reciprocating pump, which should not be greater than 2% or 3% for a pump in good condition.

pump slope
 * A slope in which pumps are operated.

pump station
 * a. In mining, a chamber near the shaft at depth, where a pump is installed.

b. An enlargement made in the shaft, slope, or entry to receive the pump. Also called pumproom. c. The site at which one or more pumps are installed along a pipeline for the purpose of forcing a fluid through the line.

pump stock
 * Lanc. See: pump tree.

pump sump
 * A tank into which fluids gravitate and from which they are recirculated by means of a pump.

pump surge
 * The pulsating effect transmitted to a pipeline or drill string at the completion of each compression stroke of a reciprocating-piston pump.

pump tree
 * Eng. A cast-iron (wrought iron was formerly used) pipe, generally 9 ft (2.7 m) in length, of which the water column or set is formed. Syn: pump stock.

punch
 * a. A tool (ram) for knocking out timbers in coal workings.

b. See: leg; punch prop.

punched screen
 * Thin plates through which holes have been punched. These may be round, rectangular, or slotted.

puncher
 * An early-model pick machine used to undermine or shear coal by heavy blows of sharp steel points attached to a piston driven by compressed air.

punching shear
 * If a heavily loaded column punches a hole through the base on which it rests, the base has failed in punching shear. This is prevented either by thickening the base or by enlarging the foot of the column so as to ensure that the allowable shear stress is not exceeded.

punch mining
 * a. Mining in which the rooms are opened off the strip mine highwall.

b. An underground method of extracting coal from finger-shaped areas of reserves not amenable to other mining methods. Openings are driven by continuous mining machines back and forth across the fingers from outcrop to outcrop leaving a pillar of coal between each cut.

punch prop
 * A short timber prop for supporting coal in holing or undercutting; a sprag.

puppet valve
 * A valve that, in opening, is lifted bodily from its seat by its spindle instead of being hinged at one side. See also: poppet; poppet valve.

puppy
 * An underground set of pumps.

pure bending
 * In mine subsidence, bending without fracture.

pure coal
 * See: vitrain.

pure culture
 * A collection of microbial cells of the same species in a container that is devoid of any other form of life.

pure oxide
 * Any of a group of refractories including alumina, magnesia, thoria, zirconia, beryllia, and ceria.

pure oxide ceramic
 * Ceramic product made from any of the pure oxides of nonmetallic materials; i.e., Al (sub 2) O (sub 3), MgO, SiO (sub 2) , etc.

pure shear
 * A strain in which a rock body is elongated in one direction and shortened at right angles to this in such an amount that the volume remains unchanged.

pure steel
 * The product of a basic open-hearth furnace refined to a point where the impurities are reduced to the lowest practicable minimum, after which copper and molybdenum are added in correct proportions.

purlins
 * Timbers spanning from truss to truss, and supporting the rafters of a roof.

puron
 * High-purity iron.

purple blende
 * An old syn. for kermesite.

purple copper ore
 * A miners' term for bornite. Syn: bornite.

purple ore
 * Sintered pyritic ore.

purpurite
 * An orthorhombic mineral, MnPO (sub 4) ; forms a series with heterosite; deep red or reddish purple; forms small, irregular masses as an alteration product of lithiophilite and triphylite; at Pala, CA; Hill City, SD; Newry, ME; and the Erongo Mountains, Namibia.

pushbutton coal mining
 * A fully automatic and remotely controlled system of coal cutting, loading, and face conveying, including self-advancing roof support systems. See also: manless coal face.

pushbutton winding control
 * A system in which the operation of the winder is similar to automatic cyclic winding, but the starting is instigated by the onsetter and banksman. When everything is ready for winding, the onsetter and banksman press their respective start pushbuttons and the winder starts, accelerates, and banks automatically without the intervention of the winding engineman. With this form of control, loading and discharging of the skips is fully automatic. See also: automatic cyclic winding; manual winding control.

pusher
 * a. A laborer who pushes loaded mine cars on tracks from underground working places to haulage roads where they are hooked up to a locomotive and hauled to the surface, shaft, or slope bottom for hoisting. A pusher may, at bituminous mines, shift empty and loaded cars in and about the tipple, where coal is prepared for market. Also called: car puller; car shifter; headsman; putter; trailer; trammer. Syn: mule; wheeler.

b. One who encourages or hastens the miners. Also called jigger boss. c. A tractor that pushes a scraper to help it pick up a load.

pusher tractor
 * A bulldozer exerting pressure on the rear of a scraper loader while the loader is digging and loading unconsolidated ground being excavated and moved during opencast mining.

push hole
 * A hole through which glass is introduced to a flattening furnace.

push-pull support system
 * A method of advancing power-operated supports on a longwall face. Double-acting hydraulic jacks are used in conjunction with supports that slide forward on the floor and provide their own abutments for both their forward movement and that of the conveyor.

push-pull wave
 * A wave that advances by alternate compression and rarefaction of a medium, causing a particle in its path to move forward and backward along the direction of the wave's advance. In connection with waves in the Earth, also known as primary wave, compressional wave, longitudinal wave, or P-wave.

push wave
 * See: P wave.

put
 * To haul by hand.

putrefaction
 * A process of decomposition of organic substances that occurs in the presence of water and with the complete exclusion of air. It is a kind of slow distillation whereby chiefly methane (CH (sub 4) ) and smaller quantities of other gaseous products, such as hydrogen (H (sub 2) ), ammonia (NH (sub 3) ), and hydrogen sulfide (H (sub 2) S), are formed. CF: disintegration.

PVC belt
 * There are two main types of belts: (1) solid woven carcass impregnated and covered with polyvinyl chloride; and (2) normal multiple construction, which has polyvinyl chloride interlayers and covers. PVC belts are now used widely in coal mines, being not only fire resistant but equal, if not better, in quality than normal rubber belting. See also: conveyor.

P wave
 * A seismic wave that propagates by alternating compressions and rarefactions in an elastic medium; the motion is in the direction of propagation. It is the type that carries sound. Syn: compressional wave; dilatational wave; irrotational wave; longitudinal wave; pressure wave; push wave.

pycnite
 * A variety of topaz occurring in massive columnar aggregates. Also spelled pychite.

pycnocline
 * A steep vertical gradient of density.

pycnometer
 * a. A device for weighing and thus determining the specific gravity of small quantities of oil or other liquids. Also spelled pyknometer.

b. A small bottle for determining the specific gravity of grains or small fragments.

pyrabol
 * See: pyribole.

pyralmandite
 * A garnet composition between pyrope and almandine. See also: pyrope.

pyralspite
 * The pyrope, almandine, spessartine subgroup of the garnet group. See also: pyrope.

pyramid
 * An open crystal form consisting of nonparallel faces that intersect the c crystallographic axis and consist of three (trigonal), four (tetragonal), six (ditrigonal, hexagonal), or eight (ditetragonal) faces meeting at a point. CF: bipyramid; hemipyramid; dome.

pyramidal
 * Descriptive of a crystal habit dominated by pyramids or bipyramids.

pyramidal garnet
 * Same as idocrase; a variety of vesuvianite.

pyramid cut
 * a. In tunnel driving or shaft sinking, a pattern of shotholes drilled so that the middle holes converge and outline a pyramid-shaped volume of rock. These holes are fired first, and thus create a free face or relieving cut.

b. This cut has received its name from the shape of the initial opening. The three or four holes are so directed that they meet at a point farthest in. The pyramid cut is mainly employed in raises and for shaft sinking but is not recommended for horizontal tunnels where a machine setup for a definite direction of the four holes cannot easily be obtained. Syn: German cut. c. This type of cut usually consists of four holes drilled to meet at a common apex in the center of the face. This arrangement permits a high concentration of explosive to be used, and the pyramid cut is therefore particularly suitable for breaking hard ground. In very hard ground the number of holes forming the cut may be increased to six. The main disadvantage of this type of cut is the difficulty in drilling the holes at the correct angles so that they will meet at the back of the cut. As in the case of the wedge cut, therefore, a hole director should be used. Also called diamond cut. d. In underground blasting, a type of cut employed in which the three cut holes in the center may be drilled to form a pyramid. Also applied to four holes meeting in a point. The simultaneous firing of these holes is somewhat equivalent to using a very heavy charge of explosive and makes a powerful blast. e. A cut in which four central holes are drilled towards a focal point, and when fired break out a tetrahedral section of strata.

pyramid-set
 * A bit crown, the face of which is covered with a series of stubby pyramids, each apex of which is set with a diamond.

pyramid structure
 * In crystallography, that of a crystal in which three or more inclined faces cut the three crystal axes.

pyrargyrite
 * A trigonal mineral, Ag (sub 3) SbS (sub 3) ; dimorphous with pyrostilpnite; rhombohedral cleavage; soft; deep red; in late-primary or secondary-enrichment veins, and an important source of silver. Syn: antimonial red silver; dark red silver ore; dark ruby silver.

pyrene
 * A tetracyclic hydrocarbon obtained from the coal-tar fraction boiling above 360 degrees C; C (sub 16) H (sub 10) ; soluble in carbon disulfide, toluene, and ligroin.

pyreneite
 * A black variety of andradite garnet. Syn: melanite.

pyrheliometer
 * An actinometer that measures the intensity of direct solar radiation.

pyribole
 * The pyroxene group plus amphibole group. See also: pyroxene.

pyricaustate
 * A general name for a fossil combustible substance.

pyrite
 * a. An isometric mineral, FeS (sub 2) ; dimorphous with marcasite; forms a series with cattierite; crystallizes in cubes and pyritohedra; sparks readily if struck by steel; metallic; pale bronze to brass yellow; hardness varies from 6.0 to 6.5; occurs in veins, as magmatic segregation, as accessory in igneous rocks, and in metamorphic rocks, in sedimentary rocks including coal seams; a source of sulfur; may have included gold. Syn: Alpine diamond; iron pyrite; fool's gold; mundic; common pyrite.

b. The mineral group aurostibite, bravoite, cattierite, erlichmanite, fukuchilite, geversite, hauerite, insizwaite, krutaite, laurite, malanite, maslovite, michenerite, penroseite, pyrite, sperrylite, testibiopalladite, trogtalite, vaesite, and villamaninite.

pyrites
 * a. Various metallic-looking sulfide minerals including iron pyrites (pyrite); copper pyrites (chalcopyrite); tin pyrites (stannite); white iron, cockscomb, or spear pyrites (marcasite); arsenical pyrites (arsenopyrite); cobalt pyrites (linnaeite); magnetic pyrites (pyrrhotite); and capillary pyrites (millerite). Without qualification it popularly refers to pyrite.

b. Stones that may be used for striking fire.

pyrites of copper
 * Common name for chalcopyrite.

pyritic
 * Of, pertaining to, resembling, or having the properties of pyrites.

pyritic smelting
 * Smelting of sulfide copper ores, in which heat is supplied mainly by oxidation of iron sulfide. Syn: oxidizing smelting.

pyritic sulfur
 * The part of the sulfur in coal that is in the form of pyrites or marcasite.

pyritiferous
 * Containing or producing pyrite.

pyritization
 * Introduction of or replacement by pyrite; e.g., the replacement of original fossil material by pyrite. A common hydrothermal introduction of pyrite specks in rock adjacent to veins.

pyritohedron
 * An isometric closed crystal form of 12 faces, each an irregular pentagon. It is named after pyrite, which characteristically has this crystal form. See also: rhombic dodecahedron CF: dodecahedron.

pyroantimonite
 * See: kermesite.

pyroaurite
 * A trigonal mineral, Mg (sub 6) Fe (sub 2) (CO (sub 3) )(OH) (sub 16) .4H (sub 2) O ; hydrotalcite group; dimorphous with sjoegrenite; occurs in goldlike submetallic scales, or brown crystals having pearly to greasy luster. A silvery white variety is called igelstromite.

pyrobelonite
 * An orthorhombic mineral, PbMn(VO (sub 4) )(OH) ; descloizite group; forms minute fire-red acicular crystals at Laangban, Sweden; a source of vanadium.

pyrobitumen
 * Any of the dark-colored, fairly hard, nonvolatile, carbon-rich material substances composed of hydrocarbon complexes, which may or may not contain oxygenated substances and are often associated with mineral matter. The nonmineral constituents are infusible, insoluble in water, and relatively insoluble in carbon disulfide.

pyrobituminous
 * Pertaining to substances that yield bitumens upon heating.

pyrochlore
 * a. An isometric mineral, (Ca,Na) (sub 2) Nb (sub 2) O (sub 6) (OH,F) ; forms a series with microlite; in pegmatites in Maine, California, Colorado, Africa, and Europe; a source of niobium. Syn: pyrrhite.

b. The mineral group including the betafite subgroup betafite, plumbobetafite, and yttrobetafite; the microlite subgroup bariomicrolite, bismutomicrolite, microlite, plumbomicrolite, and uranmicrolite; and the pyrochlore subgroup bariopyrochlore, ceriopyrochlore, kalipyrochlore, plumbopyrochlore, uranpyrochlore, and yttropyrochlore.

pyrochroite
 * A trigonal mineral, Mn(OH) (sub 2) ; brucite group; soft; pearly white darkening on exposure; has perfect basal cleavage.

pyroclast
 * An individual particle ejected during a volcanic eruption. It is usually classified according to size.

pyroclastic
 * Produced by explosive or aerial ejection of ash, fragments, and glassy material from a volcanic vent. Applied to the rocks and rock layers as well as to the textures so formed.

pyroclastic deposit
 * A deposit made up mainly of rock material that has been expelled aerially, normally explosively, from a volcanic vent, such as agglomerate, tuff, and ash. The fragments range in size from bombs and blocks to dust or ash. Such deposits are usually designated according to the lavas to which they correspond in composition.

pyrogenesis
 * A broad term encompassing the intrusion and extrusion of magma and its derivative. Adj. pyrogenic.

pyrogenetic
 * A term introduced to designate minerals, such as olivine and chromite, developed at high temperature in melts containing only a small proportion of volatile (hyperfusible or fugitive) constituents. See also: pyrogenic.

pyrogenic
 * Said of a process or of a deposit involving the intrusion and/or extrusion of magma. See also: pyrogenetic; igneous.

pyrogenic ore mineral
 * An ore mineral that crystallized as a primary magmatic mineral of igneous rocks.

pyrogenic rock
 * A rock resulting from the cooling of a molten magma; an igneous rock.

pyrognostics
 * The characteristics (such as the degree of fusibility or the flame coloration) of a mineral observed by the use of the blowpipe.

pyrolite
 * An explosive resembling gunpowder in composition.

pyrolusite
 * A tetragonal mineral, MnO (sub 2) ; rutile group; trimorphous with akhtenskite and ramsdellite; soft; metallic; steel gray; massive or reniform; a source of manganese. CF: psilomelane. Syn: polianite; gray manganese ore.

pyrolysis
 * Chemical decomposition by the action of heat.

pyrolytic graphite
 * Graphite formed by pyrolysis of a carbonaceous gas.

pyrometallurgy
 * Metallurgy involved in winning and refining metals in which heat is used, as in roasting and smelting. Practically all iron and steel, nickel and tin, most copper, and a large proportion of zinc, gold, and silver, as well as many of the minor metals, are won from their ores and concentrates by pyrometallurgical methods. It is the most important and oldest class of the extractive processes.

pyrometamorphism
 * Metamorphism produced by heat; it is a local, intense type of thermal metamorphism, resulting from unusually high temperatures at the contact of a rock with magma, such as in xenoliths. CF: igneous metamorphism; hydrometamorphism. See also: thermal metamorphism.

pyrometasomatic
 * Formed by metasomatic changes in rocks, principally in limestone, at or near intrusive contacts, under the influence of magmatic emanations and high to moderate temperature and pressure.

pyrometasomatism
 * Contact metamorphism. CF: metasomatism.

pyrometer
 * An instrument that measures high temperature, e.g., of molten lavas, by electrical or optical means. See also: optical pyrometer.

pyrometric cone
 * A small, slender three-sided pyramid made of ceramic or refractory material for use in determining the time-temperature effect of heating and in obtaining the pyrometric cone equivalent (PCE) of refractory material. Pyrometric cones are made in series, the temperature interval between successive cones usually being 20 degrees C. The best known series are Seger cones (Germany), Orton cones (United States), and Staffordshire cones (United Kingdom). See also: cone; orton cone.

pyrometric cone equivalent
 * The number of that standard pyrometric cone whose tip would touch the supporting plaque simultaneously with a cone of the refractory material being investigated when tested in accordance with ASTM Test Method C-24. Abbrev. PCE.

pyromorphite
 * A hexagonal mineral, Pb (sub 5) (PO (sub 4) ) (sub 3) Cl ; apatite group, with iron replacing lead and arsenic replacing phosphorous; sp gr, 6 to 7; in oxidized zones of lead-ore deposits. Syn: green lead ore.

pyrope
 * a. An isometric mineral, 8[Mg (sub 3) Al (sub 2) (SiO (sub 4) ) (sub 3) ]; garnet group, with Fe and Mn replacing Mg and Cr replacing Al. See also: pyralspite; pyralmandite. Crystallizes in dodecahedra and trapezohedra; deep red to black; in high-pressure ultramafic and metamorphic rocks; also in placers; a gemstone and an abrasive. See also: Cape ruby; Bohemian garnet. Syn: rock ruby; magnesium-aluminum garnet.

b. Formerly, a name for any bright red gem, such as ruby.

pyrophane
 * An opal, e.g., hydrophane, artificially impregnated with melted wax. See also: fire opal.

pyrophanite
 * A trigonal mineral, MnTiO (sub 3) ; ilmenite group; forms a series with ilmenite; blood red.

pyrophoric sphalerite
 * A variety of sphalerite that gives off sparks or glows when abraded. Some pieces are so sensitive that the effect is obtained by scratching them with a fingernail.

pyrophyllite
 * A monoclinic and triclinic mineral, Al (sub 2) Si (sub 4) O (sub 10) (OH) (sub 2) ; foliated; soft; in schists and hydrothermal veins in North Carolina, California, Newfoundland, and Japan. Syn: pencil stone. See also: G stone.

pyrophysalite
 * A coarse opaque variety of topaz from Finbo, Sweden. Also spelled physalite.

pyropissite
 * An earthy nonphosphatic pyrobitumen composed primarily of water, humic acid, wax (a source of "montan wax"), and silica, associated with brown coal called pyropissitic brown coal.

pyroradiation pyrometer
 * A self-contained instrument with the millivoltmeter mounted in the pyrometer tube; the radiant energy is concentrated by means of an objective lens (quartz or fluorite) rather than by a reflecting mirror.

pyroretin
 * A brittle, brownish-black resin that occurs in brown coal near Aussig, Bohemia; sp gr, 1.05 to 1.18.

pyrosmaltite
 * Any member of the hexagonal mineral series, ferropyrosmaltite-manganpyrosmaltite, (Fe,Mn) (sub 8) Si (sub 6) O (sub 15) (OH,Cl) (sub 10).

pyrostibite
 * See: kermesite. Also spelled pyrostibnite.

pyrostibnite
 * See: kermesite. Also spelled pyrostibite.

pyrostilpnite
 * A monoclinic mineral, Ag (sub 3) SbS (sub 3) ; dimorphous with pyrargyrite; red. Syn: fireblende.

pyrosulfuric acid
 * a. A heavy, oily, strongly corrosive liquid H (sub 2) S (sub 2) O (sub 7) that consists of a solution of sulfur trioxide in anhydrous sulfuric acid. It fumes in moist air and reacts violently with water with the evolution of heat.

b. A solution of sulfur trioxide in sulfuric acid; H (sub 2) S (sub 2) O (sub 7). Colorless to dark brown depending on purity; hygroscopic.

pyroxene
 * a. A group of chiefly magnesium-iron minerals including diopside, hedenbergite, augite, pigeonite, and many other rock-forming minerals. Although members of the group fall into different systems (orthorhombic, monoclinic, and triclinic), they are closely related in form, composition, and structure. See also: acmite; aegirite; augite; diallage; enstatite; hypersthene.

b. The mineral group aegirine (Ae), aegirine-augite, clinoenstatite, clinoferrosilite, diopside (Di), donpeacorite, enstatite (En), essenite (Es), ferrosilite (Fs), hedenbergite (Hd), jadeite (Jd), jervisite (Je), johannsenite (Jo), kanoite (Ka), kosmochlor (Ko), natalyite, omphacite, petedunnite (Pe), pigeonite, and spodumene (Sp). Some former names relegated to synonyms include acmite = aegirine, bronzite = enstatite, clinohypersthene = clinoenstatite or clinoferrosilite, diallage = altered diopside or other pyroxene with good (100) parting, eulite = ferrosilite, fassaite = ferrian aluminian diopside or augite, ferroaugite = augite, ferrosalite = hedenbergite, hiddenite = spodumene, hypersthene = enstatite or ferrosilite, kunzite = spodumene, salite = diopside, titanaugite = titanian augite, uralite = pseudomorphous amphibole after pyroxene, and ureyite = kosmochlor. Pyroxenes (px) are either monoclinic (clinopyroxenes, cpx) or orthorhombic (orthopyroxenes, opx). General formula: AB (sub 2) ZO (sub 6) : A = Ca, Fe (super 2+), Li, Mg, Mn (super 2+) , Na, Zn; B = Al, Cr (super 3+) , Fe (super 2+) , Fe (super 3+) , Mg, Mn (super 2+) , Sc, Ti, V (super 3+) ; Z = Al, Si. Their structures are built from single chains of silica tetrahedra each sharing two oxygens, with a silica:oxygen ratio of 1:3, electrostatic neutrality being maintained by cross-linking cations. Crystals are prismatic with prismatic cleavage at 87 degrees and 93 degrees. Colors are mostly greens, but range from white to black. Etymol: Greek pyros (fire) + xenos (stranger) from a mistaken belief that they were only accidently caught up in lavas. See also: aegirine. CF: amphibole; pyribole.

pyroxene perthite
 * Lamellar intergrowths of pyroxene of different kinds, as with the feldspars. Also pyroxene microperthite, pyroxene cryptoperthite.

pyroxenite
 * A coarse-grained, holocrystalline igneous rock consisting of 90% pyroxenes. It may contain biotite, hornblende, or olivine as accessories.

pyroxenoid
 * Single-chain silicates with individual silica tetrahedra twisted relative to the pyroxene chains, resulting in triclinic symmetry; e.g., the wollastonites, rhodonite, and pectolite.

pyroxmangite
 * A triclinic mineral, MnSiO (sub 3) ; forms a series with pyroxferroite where iron replaces manganese; forms brown cleavable masses near Iva, SC; Homedale, ID; Sweden; and Scotland.

pyrrhite
 * See: pyrochlore.

pyrrhoarsenite
 * See: berzeliite.

pyrrhotine
 * See: pyrrhotite.

pyrrhotite
 * A monoclinic and hexagonal mineral, FeS ; invariably deficient in iron; variably ferrimagnetic; metallic; bronze yellow with iridescent tarnish; in mafic igneous rocks, contact metamorphic deposits, high-temperature veins, and granite pegmatites. Where associated with pentlandite and nickel replaces iron, it is a source of nickel. Also spelled pyrrhotine. Syn: magnetic pyrite; dipyrite.