3" Quartz, Calcite and Loellingite Association - Inner Mongolia

loellingite (or löllingite) is an iron arsenide mineral with the chemical formula FeAs₂. The crystals are often twinned and exhibit a silvery metallic luster. It is named after the Lölling mining district in Carinthia, Austria, the site from which it was first described in 1845. It typically forms in association with arsenopyrite, and it can be difficult to tell the two apart.

Toxicity Warning: Loellingite contains arsenic and can be harmful if inhaled or swallowed. Most of the risk is posed by long-term, chronic exposure to its dust or fumes. While a crystal sitting on your shelf doesn't pose a health risk, you should wash your hands after handling and keep it out of reach of children.