lapillus

Noun

 * 1) A fragment of lava ejected from a volcano.
 * 2)  One of the otoliths in finfish.
 * 1)  One of the otoliths in finfish.

Etymology
Diminutive from, likely originally formed on the oblique stem as.

Noun

 * 1) A small stone, pebble.
 * 2) Stone in the bladder, gravel, calculus.
 * 3) A precious stone, gem, jewel; marble.
 * 4) A tombstone.