Wardsmithite, 5CaO·MgO·12B2O3·30H2O, is a new borate found at two localities in the Death Valley region, Inyo Count}, California, on weathered veins of colemanite or priceite in the Furnace Creek Formation (Pliocene). It occurs as nodules and coatings in gowerite, ulexite, and colemanite.

The mineral is hexagonal (or pseudohexagon al) with a platy habit and cleavage {0001P}. Typically, it occurs as aggregates of subparallel plates to 75 μm in diameter, uncommonly as single crystals to 15 nm in diameter. The strongest lines in the X-ray powder diffraction pattern (unindexed) are, in Å: 13.5 (100), 12.3 (62), 6.12 (55), 3.358 (51), 4.721 (42), 2.744 (26).

Infrared absorption peaks (in cm-1) are 790, 810, 890, 1000, 1070, 1335, and 1615.

Crystals of wardsmithite are colorless. Optically it is uniaxial (—), with ω = 1.490 ± 0.002, ϵ = 1.476±0.002. Hardness is 212; specific gravity, 1.88 ± 0.02.

Chemical analysis gave, in weight percent, B2O3 48.58, CaO 16.50, MgO 2.26, H20 32.44, sum 99.78. Spectroscopic analysis showed Si, Al, Na, Mn, Ba, Cu, and Pb in small amount.

Wardsmithite is named after Ward C. Smith, geologist of the U.S. Geological Survey

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