Superb QUARTZ, SIDERITE, FLUORAPATITE (DT) *Panasqueira, Portugal* For Sale

Panasqueira has operated continuously since 1898 and remains the world's benchmark locality for fluorapatite and ferberite. Its hydrothermal quartz veins also produce combination pieces — quartz with siderite, fluorapatite, and arsenopyrite — that fill museum cases from the Natural History Museum in London to the American Museum of Natural History in New York.

This large cabinet crystal measures 19.5 cm and is doubly terminated, with both ends presenting well-formed rhombohedral faces and strong vitreous luster. The clean prism faces are transparent to translucent with characteristic horizontal striations and phantom zones visible in the interior. Along one edge and across the back face, a dense band of tan-to-olive rhombohedral siderite crystals forms a thick, well-individualized crust — the macros show proper crystal development throughout, not just a granular coating — accented by scattered metallic pyrite and arsenopyrite that catch the light against the siderite matrix. The fluorapatite component will fluoresce orange under shortwave UV. At 848 grams, this is a substantial piece with real presence on a shelf.

Doubly terminated Panasqueira quartz of this size, with the associated siderite suite still intact and undamaged, doesn't come up often. Ex Weinrich, Level 3. A strong piece for any serious Panasqueira or world quartz collection, at a reallly good price for the caliber of material.