Kermes

Kermes, a dyestuff obtained from an insect (see DYEING). The name is also given to a cherry-red mineral, usually in tufts of capillary crystals; a mixture of sesquioxide and sesquisulphide of antimony; approximate composition $(Sb\_2O\_3)\_2Sb\_2O\_3$. It was formerly much used for the same purposes as James's Powder (q.v.).