This flat contains a collection of Phurcalite crystals from the Posey Mine, USA. The specimens are mostly developed as flat crystal coatings with yellow to yellow green crystal growth on grey to brown matrix. Under UV light, the Phurcalite crystals show a clear and distinct fluorescence, making this flat especially attractive for collectors of UV reactive minerals. The variation in crystal coverage, color intensity, and surface structure within the flat provides an excellent overview of the visual characteristics of this rare uranium mineral.
Geology & Origin
Phurcalite is a rare secondary uranyl phosphate that forms in the oxidation zones of uranium rich deposits. The Posey Mine in the USA is a well known locality for a variety of fluorescent uranium minerals. Phurcalite forms through the alteration of primary uranium minerals under oxidizing conditions and is commonly associated with other secondary uranium phases. Due to its rarity, UV activity, and characteristic appearance, Phurcalite from the Posey Mine is highly sought after by collectors.