trichite

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A small, dark, needle-shaped crystal.

Century Dictionary and Cyclopedia

1. n. One of the minute acicular crystals of which the starch-grains of plants are supposed to consist.
2. n. A kind of flesh-spicule or microsclere of some sponges; a fibrillate spicule, in which the silica, instead of being deposited in concentric coatings around an axis, forms within the scleroblast a sheaf of exceedingly fine fibrillæ which may be straight or twisted; also, one of these fibrillæ: as, “fine fibrillæ or trichites,”
3. n. In lithology, one of various dark-colored (or even black) opaque microliths, having more or less of a curved and twisted form: frequently seen in thin sections of vitreous rocks, especially in obsidian.
4. Same as trichitic.

Wiktionary

1. n. mineralogy A kind of crystallite resembling a bunch of hairs, common in obsidian.
2. n. zoology A delicate, hair-like siliceous spicule, found in certain sponges.

GNU Webster's 1913

1. n. (Min.) A kind of crystallite resembling a bunch of hairs, common in obsidian. See Illust. of Crystallite.
2. n. (Zoöl.) A delicate, hairlike siliceous spicule, found in certain sponges.