Class

non-silicate mineral

Compound type

borate

Chemical functions

	Function	Number	Relevance
	$R-OH$	2	main

Chemical bonds

	Bond	Number	Relevance
	$\geq B-O-$	8
	$-O-H$	2	main

Oxides

Formula	$MgO$	$B_{2}O_{3}$	$H_{2}O$
Mass fraction (%)	24.58	42.46	32.96

Strunz

Class

borates (06)

Division

diborates (06.B)

Family

Neso-diborates with double tetrahedra B2O(OH)6; 2(2T) (06.BB)

Code

06.BB.05

Dana

Major class

carbonates, nitrates, borates (V)

Class

anhydrous borates containing hydroxyl or halogen (25)

Type

25.02

Group

-Pinnoite- group (25.02.03)

Code

25.02.03.01

Phase type

crystalline

Crystal system

tetragonal

Crystal class

pyramidal

Crystal class symbol

4 (C4)

Crystal spacegroup

P4(2)

Molar mass

163.97 $g/mol$

Density

2.29 $g/cm^3$

Refringence type

uniaxial

Refringence sign

positive

Birefringence

0.010

Refraction index $n_{\alpha}$

1.565

Refraction index $n_{\beta}$

1.575

Color

colorless, yellow, yellow green, light yellow

Diaphaneity

translucent

Luster

vitreous