Borax
Borax is a borate mineral recognized among collectors for its crystal form and distribution, with known Chinese sources.
Borax is a soft white sodium borate that crystallises from drying desert lakes — the classic 'twenty-mule-team' mineral of Death Valley.
About Boraxextended article
Borax is a hydrated sodium borate, one of the most important boron minerals and a familiar household chemical. It crystallises as soft, pale, prismatic crystals and crusts where boron-rich desert lakes dry up.
Identifying borax
Borax is very soft (2–2.5), light, and colourless to white or grey, with a dull to glassy lustre. Crystals slowly lose water and become chalky white on the surface when exposed to dry air, and it dissolves readily in water.
Where it is found
Borax forms in evaporite deposits in arid basins. The classic source is Death Valley and the deserts of California, where it was hauled out by the famous twenty-mule teams; other major deposits occur in Turkey and Tibet.
About Borax
Borax belongs to the borate class in the borax group and has the chemical formula Na2(B4O5)(OH)4·8H2O. It crystallizes in the monoclinic system and is relatively soft, requiring careful handling.
Identification & care
Crystals commonly develop as prismatic, tabular, massive; dehydrates to white powdery tincalconite on surface. Its color range is broad, including colorless, white, pale gray, and pale blue-green. The luster is vitreous to resinous, the streak is white, and specimens range from transparent to translucent. The cleavage is perfect {100}. The fracture is conchoidal, which aids identification.
Collector context
Collector notes
Among collectors of crystallized species, Borax is a recognized reference. Borax is widely represented across Chinese provinces, including Tibet, Inner Mongolia, Qinghai.
Frequently asked questions
What is Borax?
Borax is a borate mineral recognized among collectors for its crystal form and distribution, with known Chinese sources.
What crystal system does Borax belong to?
Borax crystallises in the Monoclinic crystal system.
Where is Borax found?
Notable localities for Borax include Salar del Hombre Muerto.
References & databases
Mindat.org is the world’s largest open mineralogy database. Our descriptions are written independently and fact-checked.