petrogr.

Noun

 * 1) * 1997: Oxford English Dictionary, lithotype, n. (additions series 1997)
 * Add: 4. Petrogr. A macroscopically visible constituent of coal distinguished by its physical characterisitics; a macroscopically distinguishable variety of coal. Cf. maceral n.
 * Add: 4. Petrogr. A macroscopically visible constituent of coal distinguished by its physical characterisitics; a macroscopically distinguishable variety of coal. Cf. maceral n.