Benitoite with Neptunite - image 1

Benitoite with Neptunite

Unknown Owner
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Nearly forty Neptunite crystals, and eighteen Benitoite crystals: This 16 centimeter plate is chock-full of the two signature species of the California State Gem Mine (or Dallas Gem Mine, or Benitoite Mine, et cetera...). This iconic pair of minerals is sprinkled beautifully across the white and grey matrix of natrolite (white) and crossite (blue rock) etched out to reveal the treasure inside. Neptunite is found in a few localities around the world, but the ones from this mine are by far the best representation of the species. Its sibling, Benitoite, is even more elusive, with crystals being found exclusively in California, with the exception of a handful of 1-2mm examples from Japan. This specimen features one particularly exceptional crystal at the far right. The Benitoite fluoresces a bright blue under shortwave UV light.

Product details

SizeLarge Cabinet
Dimensions14.0 x 16.0 x 4.0 cm
Added on06/14/2025

Known provenance

DateCollectorAcquisition price
03/2025Unknown Owner$3,750.00
purchased from Heritage Auctions (Dan Kennedy's collection)
Dan KennedNot disclosed

Learn more

Neptunite
Mineral guide
Learn about Neptunite
jet-black, high-luster prisms with natrolite and benitoite; California State Gem Mine specimens exemplify striking contrast, rarity, and display.
Neptunite
Regional guide
Neptunite from California State Gem Mine, USA
California State Gem Mine, San Benito County - famed for black neptunite with blue benitoite in natrolite, offering dramatic contrast and collector appeal.