Benitoite with Neptunite
specimen number:
2242101
location:
Gem Mine, San Benito Co., California, USA
description: The Gem Mine, also known as the Dallas Gem Mine, is located in the remote Diablo Range of San Benito County, California, and is the only commercial source of gem-quality benitoite in the world. Geologically, the mine is situated within a unique body of glaucophane schist and serpentinite where rare barium-titanium silicate fluids crystallized during high-pressure, low-temperature metamorphism. Benitoite is famously recognized for its striking sapphire-blue color, high dispersion, and rare ditrigonal-dipyramidal crystal symmetry, often occurring in association with white natrolite and black neptunite. Historically, the deposit was discovered in 1907 by James Couch, who initially mistook the blue crystals for sapphires. Mining and quarrying at the site were most active during the early 1900s under the San Benito Gem Company and again during several revival periods in the late 20th century. While the primary underground and open-cut mining operations have transitioned to smaller-scale specimen recovery and fee-digging for collectors, the site remains the definitive locality for California's official state gemstone. Today, the mine continues to be a site of significant mineralogical interest and a source of world-class specimens through 2026.
Sharp blue lustrous crystals of benitoite measuring to 2.0 cm in size across the top of a white natrolite matrix with minor neptunite. In outstanding condition. A wonderful high quality example for the species.
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