Home > American Localities – September 25 > MS0774 Phosphosiderite
Phosphosiderite - Sold
- Stewart mine
- Pala
- San Diego County
- California
- U.S.A.
- 4.8 by 3.4 by 3.1 cm. – Thumbnail specimen (fits into a 2.5 cm cube)
Phosphosiderite is the I.M.A. accepted name for the monoclinic polymorph of orthorhombic strengite (once known as metastrengite). Bruhns and Busz (1890) described the mineral from a locality in Germany, and named it for the composition (iron phosphate). Moore (1966) solved the crystal structure. In this example, alteration of primary triphylite-lithiophilite resulted in the redeposition of Fe3+ and PO4 as a purple encrustation of phosphosiderite. The purple coverage area is approximately 2.9 by 1.4 cm/ This is an interesting example of pegmatite alteration chemistry, from a well studied area. This specimen was part of the personal collection of Ralph Merrill, proprietor of the prolific mail order business Minerals Unlimited.