Name/Title
CrocoiteEntry/Object ID
2004.63.7Description
About Crocoite
Formula: PbCr6+O4
Colour: Orange, red, yellow; orange-red in transmitted light.
Lustre: Sub-Adamantine, Sub-Vitreous, Resinous, Waxy
Hardness: 2½ - 3
Specific Gravity: 5.97 - 6.02
Crystal System: Monoclinic
Name: Originally recognized by Mikhail Vassil’evich Lomonosov in 1763 as a red lead ore. Johann Gottlob Lehmann in 1766 named it Nova Minera Plumbi. Various authors later gave the mineral a name signifying the presence of lead and the color red: minera plumbi rubra (Wallerius, 1778), Rothes bleierz (Werner, 1774), and Plomb rouge (Macquart, 1789). After the element chromium was announced in 1798, a new series of names was applied to the species: Plomb chromaté (Haüy, 1801), Kallochrom (Hausmann, 1813), etc. Renamed Crocise by François Sulpice Beudant in 1832 and Krokoisite by Franz von Kobell in 1838. Translated to the current pronunciation, Krokoit, by Johann August Breithaupt in 1841. Named Beresofite in 1844 by Charles Upham Shepard. Named Lehmannite by Henry J. Brooke and William H. Miller in 1852. The name crocoite comes from the Greek κρόκος "crocon" = saffron, alluding to the saffron-orange color of its powder.
Type Locality: Tsvetnoi Mine, Uspenskaya Hill, Berezovsk deposit, Beryozovsky, Sverdlovsk Oblast, Russia
Crocoite is commonly found as crystals, usually as long prismatic crystals and more rarely as equant crystals, but are most often poorly terminated, and are usually of a bright hyacinth-red color, which are translucent and have an adamantine to vitreous lustre. When fine-grained it can be bright yellow to orange, and some crystals are dark red.