Teruggite

Teruggite is a mineral with the chemical formula Ca₄MgAs₂B₁₂O₂₂(OH)₁₂·12H₂O. It is colorless. Its crystals are monoclinic prismatic. It is transparent. It is not radioactive. It has vitreous luster. Teruggite is rated 2.5 on the Mohs Scale of hardness.

Teruggite
General
Category	Nesoborates
Formula	Ca4MgAs2B12O22(OH)12·12H2O
IMA symbol	Tgg[1]
Strunz classification	6.FA.25
Crystal system	Monoclinic
Crystal class	Prismatic (2/m) (same H-M symbol)
Space group	P21/a