Bakerite

Bakerite is the common name given to hydrated calcium boro-silicate hydroxide, a borosilicate mineral (chemical formula Ca₄B₄(BO₄)(SiO₄)₃(OH)₃·(H₂O)) that occurs in volcanic rocks in the Baker, California area.^[1] Discredited mineral: IMA2016-A.

Bakerite
Bakerite sample
General
Category	Nesosilicate
Formula	Ca4B4(BO4)(SiO4)3(OH)3·H2O
Strunz classification	9.AJ.20
Crystal system	Monoclinic
Crystal class	Prismatic (2/m) (same H-M symbol)
Space group	P21/c
Unit cell	a = 4.85 Å, b = 7.627 Å, c = 9.659 Å; β = 90.255°; Z = 1
Identification
Color	Colorless, white
Mohs scale hardness	4+1⁄2
Luster	Vitreous, dull
Diaphaneity	Translucent
Specific gravity	2.88
Optical properties	Biaxial (-)
Refractive index	nα = 1.624 nβ = 1.635 nγ = 1.654
Birefringence	δ = 0.030
2V angle	Measured: 87° to 88°

It was first described in 1903 for an occurrence in the Corkscrew Canyon Mine of the Black Mountains, Furnace Creek District, Death Valley National Park, Inyo County, California, US.^[2] It was named for Richard C. Baker, a director of the Pacific Coast Borax Company.^[3][4]