Veatchite

Veatchite is an unusual strontium borate, with the chemical formula Sr₂B₁₁O₁₆(OH)₅·H₂O. There are two known polytypes, veatchite-A and veatchite-p.[4]

Veatchite
Veatchite-p, Billie Mine, Death Valley, California
General
Category	Phylloborates
Formula (repeating unit)	Sr2B11O16(OH)5 · H2O
Strunz classification	6.EC.15
Crystal system	Monoclinic
Crystal class	Domatic (m) (same H-M symbol)
Space group	Aa
Unit cell	a = 20.81 Å, b = 11.74 Å c = 6.63 Å; β = 92.03°; Z = 8
Identification
Color	Colorless to white
Crystal habit	Flattened platey to prismatic crystals, diverging fibrous clusters and cross fiber veinlets
Cleavage	Perfect on {010}, indistinct on {001}
Mohs scale hardness	2
Luster	Vitreous to pearly
Diaphaneity	Transparent to translucent
Specific gravity	2.62
Optical properties	Biaxial (+)
Refractive index	nα = 1.551 nβ = 1.553 nγ = 1.620
Birefringence	δ = 0.069
2V angle	Measured: 37°
References	[1][2][3]

Veatchite was discovered in 1938, at the Sterling Borax mine in Tick Canyon, Los Angeles County, California. Veatchite is named to honor John Veatch, the first person to detect boron in the mineral waters of California.