CROCOITE, a mineral consisting of lead chromate (PbCr04), and crystallizing in the monoclinic system. It is sometimes used as a paint, being identical in composition with the artificial product chrome-yellow. It is found as well-developed crystals of a bright hyacinth-red colour, which are translucent and have an adaman tine to vitreous lustre. On exposure to light much of the trans lucency and brilliancy is lost. The streak is orange-yellow; hardness 2 1-3 ; sp. gr. 6.o. Crystals were first found in the Urals in 1763 in quartz-veins traversing granite or gneiss. Gold is often found associated with this mineral. Crystals far sur passing in beauty any previously known have been found in the Adelaide mine at Dundas, Tasmania; they are long, slender prisms, 3 or 4in. in length, with a brilliant lustre and colour.
(L. J. S.)