Home > American Minerals II – April 7 > MS1549 Gerstleyite


Gerstleyite is a hydrous sodium antimony sulfide (Frondel & Morgan, 1956). Nakai & Appleman (1981) solved the crystal structure, placing gerstleyite among the sulfosalt minerals (Moëlo et al., 2008). The mineral name honors James M. Gerstley (1907-2007), president of the Pacific Coast Borax Company. Pacific Coast Borax sponsored an old-time radio show and later a television program, Death Valley Days, in order to promote its 20 Mule Team products.

Gerstleyite here forms a fine-grained red mass, 13 by 8 mm, in clay. The friable matrix consists of colorless kernite splinters and powdery white tincalconite, both in greenish-gray clay characteristic of this locality. The matrix will not survive washing in water; it would disintegrate. Gerstleyite is known only from the Kramer deposit. This piece was formerly in the collection of Vince Morgan (1908-1995), second author of the original description. Morgan's label as well as a Mineralogical Research Company label accompany the specimen.

Price: $200

Item code: MS1549

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