Chalcedony (good quality) (ex Brian Kosnar Collection)

Item Description

According to mindat.org, Chalcedony is "traditionally defined as a fibrous cryptocrystalline variety of Quartz, more recently, it has been shown that much Chalcedony is a mixture of Quartz and Moganite, another silica mineral. This piece is one of the better quality Chalcedony specimens I have seen from the Slanec Quarry in Slovakia. The individual "spheres", which measure up to 1.2 cm across, are actually somewhat lustrous, and have more of a milky or porcelain appearance compared to many other Chalceondy specimens that I have seen from this locality, despite some crazing. This is more than a reference piece, and would make a great addition to a Quartz collection, or a collection of European minerals.