benitoite

mineral

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June 22, 2026

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cyclosilicate Blue benitoite crystals formed on a sample of natrolite.

Benitoite is a mineral composed of sapphire-blue crystallized barium titanosilicate, with the chemical formula BaTiSi₃O₉. It is sometimes used as a gemstone. The name "benitoite" originates from San Benito County in California, where it was discovered. This mineral is distinct from benjaminite, which is a different mineral consisting of sulfobismuthite of lead, silver, and copper.12

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mineral
Cyclosilicates
The rare titanosilicate benitoite (BaTiSi₃O₉) is the only mineral that is built with the simple Si₃O₉ ring. Axinite [(Ca, Fe, Mn)₃Al₂(BO₃)(Si₄O₁₂)(OH)] contains Si₄O₁₂ rings, along with BO₃ triangles and OH groups. The two common and important cyclosilicates,
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The rare titanosilicate benitoite (BaTiSi₃O₉) is the only mineral that is built with the simple Si₃O₉ ring. Axinite [(Ca, Fe, Mn)₃Al₂(BO₃)(Si₄O₁₂)(OH)] contains Si₄O₁₂ rings, along with BO₃ triangles and OH groups. The two common and important cyclosilicates,
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