What is "stephanite"

Brittle \Brit"tle\, a. [OE. britel, brutel, AS. bryttian to dispense, fr. bre['o]tan to break; akin to Icel. brytja, Sw. bryta, Dan. bryde. Cf. Brickle.] Easily broken; apt to break; fragile; not tough or tenacious.

Farewell, thou pretty, brittle piece Of fine-cut crystal.
--Cotton.

Brittle silver ore, the mineral stephanite.

n. (context mineralogy English) A sulfide mineral of silver and antimony

Stephanite is a silver antimony sulfosalt mineral with formula: Ag Sb S It is composed of 68.8% silver, and sometimes is of importance as an ore of this metal.