Borax
Image: Robert M. Lavinsky (CC BY-SA 3.0)
Mineral NameBorax
Chemical FormulaNa₂B₄O₇·10H₂O
Mohs Hardness2
Crystal Systemmonoclinic
Lustervitreous
Streak Colorwhite
Cleavageperfect on {100}, good on {110}
Fractureconchoidal
Specific Gravity1.72
Colorswhite, colorless, pale gray, pale blue
Transparencytransparent/translucent
Type LocalityKramer Borate deposit, Boron, Kramer District, California, USA
Mineral GroupBorates
Usescleaning products, detergents, insecticides, flux in metallurgy, glass manufacturing, ceramics
Associated Mineralstincalconite, halite, gypsum, colemanite, kernite
Raritycommon
Description
Borax typically forms as white to colorless, often blocky or tabular crystals, which can appear translucent to opaque. The specimen shows white, somewhat blocky crystals, some with a slightly powdery appearance due to alteration.
Geological Context
Borax is an evaporite mineral, forming in arid regions from the evaporation of saline lake waters or playas. It is often found in large, bedded deposits.
