Emily Dickinson Lexicon

MO'CHA-STONE, n. [from Mocha, in Arabia.]

Dendritic agate; a mineral in the interior of which appear brown, reddish brown, blackish or green delineations of shrubs destitute of leaves. These in some cases may have been produced by the filtration of the oxyds of iron and manganese; but in other cases they appear to be vegetable fibers, sometimes retaining their natural form and color, and sometimes coated by oxyd of iron. Cleaveland.