Specimen of the Month from the KGS Collection: Crocoite
Crocoite is a rare and unusual mineral, and this Tasmanian specimen on display in the Mining and Mineral Resources Building on the UK campus was bought by KGS many years ago. Crocoite is a lead chromate, consisting of a lead and chromium oxide that has a high specific gravity. It is relatively soft and is sometimes confused with wulfenite, a lead molybdenum oxide that has a square and tabular habit (the shape of an individual crystal or crystal group) and more yellowish color.
Crocoite was discovered in the late 1700s and occurs in the oxidized zone of lead deposits, which is sometimes associated with quartz and gold veins. It is renowned for its bright red to orange color, slender columnar structure, and interlocking crystals. It has been found at numerous places, including the United States, but the most famous locality is in Tasmania, a south Australian island. When these magnificent crystals were found at the Tasmanian lead mines, crocoite quickly catapulted onto the international collector stage.
Because crocoite contains lead and chromium, it is somewhat toxic, so take care in handling one of these specimens. Exposure to sunlight may dampen the color and luster of the specimen.