Kernite

Formula:  Na₂B₄O₆(OH)₂ ^. 3H₂O

Origin of name:  From locality; Kern Co., California

Crystal system:  Monoclinic

Crystal class:  2/m

Twinning:  On {110}

Unit cell: a = 7.02 Ǻ, b = 9.15 Ǻ, c = 15.68 Ǻ, β = 108.9°

Colour:  Colourless; white when surface altered

Diaphaneity: 

Luster:  Dull to vitreous, silky or pearly on cleavage

Habit:  Crystals nearly equant; massive, fibrous structure, cleavable

Hardness:  2.5 to 3

Specific gravity:  1.91

Cleavage:  3; {100} and {001} perfect; {-201} distinct

Tenacity: 

Streak: 

Synonyms/varieties:

Comments:  Opaque when surface altered