Crandallite

Crandallite is a rare calcium aluminum phosphate hydroxide hydrate and part of the Plumbogummite Group. It is the calcium analogue of plumbogummite and the phosphate analogue of arsenocrandallite. Crandallite forms minute triclinic (trigonal), sub-vitreous to dull, yellow to white-gray, prisms terminated by {0001}, or as rosettes of fibers. It occurs abundantly associated with a variety of secondary phosphates in sedimentary variscite phosphate nodules at the type locality: Brooklyn mine, Silver City, Tintic district, East Tintic Mts, Juab Co., Utah, USA. It also occurs in late-stage phosphate mineralization in granite pegmatite at the Everly and Hugo pegmatite mines, Keystone, Pennington Co., South Dakota, USA; and in phosphate-bearing rock fractures or in sedimentary layers in Lawrence Co., Indiana and Garland Co., Arkansas, USA. Crandallite was named in 1917 for mining engineer, Milan Lucian Crandall, Jr. previously of the Knight Mining Company, Provo, Utah, USA.

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