Inyoite, like other borates, is a mineral that is complex is found in playa lakes and other evaporite deposits. It is rarely available as a gem that is faceted. Inyoite is one particular gems that are unusual are water soluble.

Distribution: in america, in California, from an adit on Mount Blanco, Furnace Creek district, Death Valley, Inyo Co., plus in the Kramer borate deposit, Boron, Kern Co. From Hillsborough and Wentworth, brand new Brunswick, Canada. In big amounts in the Inder boron deposit, Kazakhstan. From many deposits in the Bigadi¸c borate region, Balikesir Province, Turkey. In Argentina, through the Loma Blanca deposit, eight km southwest of Coranzul´i, Jujuy Province; within the Tincalayu borax deposit, Salar del Hombre Muerto, and during the Monte Azul mine, south of Sijes, Salta Province. From Laguna Salinas, about 65 km east of Arequipa, Arequipa Province, Peru.

Category: Nesoborates
Chemical Formula: CaB3O3(OH)5 • 4(H2O)
Hydrated Calcium Borate Hydroxide
Molecular Weight: 277.60 gm
Composition: Calcium 14.44 % Ca 20.20 % CaO
Boron 11.68 % B 37.62 % B2O3
Hydrogen 4.72 % H 42.18 % H2O
Oxygen 69.16 % O
  100.00 % 100.00 % = TOTAL OXIDE


Crystallography: Monoclinic – Prismatic
Crystal Habit: Typically as crystals, short prismatic along [001], tabular on {001}, exhibiting prominent {110} and {001} and a dozen other minor forms, to 2.5 cm; in cockscomb aggregates of pseudorhombohedral crystals; also coarse spherulitic, granular.
Twinning: None


Cleavage: Good on {001}, Distinct on {010}
Fracture: Irregular/Uneven
Tenacity: Brittle
Moh’s Hardness: 2.0
Density: 1.875 (g/cm3)
Luminescence: None
Radioactivity: Not Radioactive
Other: Soluble in hot water and dilute acids


Color: Colorless, White upon dehydration, Pinkish White with impurities
Transparency: Transparent, Translucent upon dehydration
Luster: Vitreous
Refractive Index: 1.490 – 1.520  Biaxial ( – )
Birefringence: 0.0250
Dispersion: Relatively Weakt; r < v
Pleochroism: None