Admontite

Formula:  MgB₆O₁₀·7H₂O
 

Origin of name:  after its discovery locality at Schildmaur, Admont, Austria

Crystal system:  Monoclinic

Crystal class: 2/m

Twinning:

Unit cell: a = 12.68 Å, b = 10.07 Å, c = 11.32 Å, β = 109.68°

Colour:  Colourless

Diaphaneity: Transparent to translucent

Luster: Vitreous

Habit: Crystals poorly developed or corroded

Hardness: 2-3

Specific gravity:  1.83

Cleavage: 

Tenacity: Conchoidal fracture

Streak:

Synonyms/varieties:

Comments: Slowly decomposes in water. Found in gypsum deposit.