Emily Dickinson Lexicon

CACH'O-LONG, n. [said to be from Cach, the name of a river in Bucharia, and cholon, a Calmuc word for stone.]

A variety of chalcedony, which is a subspecies of quartz, usually milk-white, sometimes grayish or yellowish white; opake or slightly translucent at the edges. Its fracture is even, or conchoidal with large cavities, sometimes dull, sometimes pearly or glossy. It often envelops common chalcedony, the two minerals being united by insensible shades. It also associates with flint and semi-opal. – Cleaveland.