SPINEL; SPINELLE n.
and various colors, as red, green, blue, brown, and black, the red variety being the gem spinel ruby. It consist essentially of alumina and magnesia, but commonly contains iron and sometimes also chromium.
GEM n.
A precious stone of any kind, as the ruby, emerald, topaz, sapphire, beryl, spinel, etc., especially when cut and polished for ornament; a jewel. Milton.