Coquimbite, Monte Arsicco Mine, Tuscany, Italy

When I first saw this specimen I thought it was a apatite from Portugal or Brazil. The purple colour and hexagonal form certainly threw me way off course. However, this is actually a rare hydrated iron sulphate called coquimbite. The mineral crystalizes in the trigonal system so we can call these particular crystals "pseudo-hexagonal". The Monte Arsicco Mine has recently yielded world-class examples of the species with crystals reaching 3 cm. I have several examples with this piece being my finest. The two mains crystals reach 2 cm each so this is a high-quality specimen. The colour is magnificent and almost looks artificial. Be careful with these specimens, however, as they are very sensitive to humidity and dehydration. Interestingly, coquimbite has recently been studied for its unique magnetic properties including antiferromagnetic interactions. Enclosed in an air-tight acrylic display box to prevent dehydration. From: Monte Arsicco Mine, Sant' Anna di Stazzema, Tuscany, Italy. Dimensions: 4 cm x 5 cm