Pyrite
 
Origin: Dongchuan Cu ore field, Yunnan, China
 
Size: 88 mm x 92 mm; Concretion size: 64 mm x 56 mm
 
What an amazing and fascinating specimen of this rare Pyrite concretion in matrix. The small, sparkling, metallic Pyrite crystals have formed in amazingly concentric "rings" on a flattened "sphere" of shale. A beautiful cabinet specimen that displays perfectly.
These don't come by very often at all.