Alpeite

Alpeite (IMA symbol: Apt^[1]) is a calcium manganese magnesium silicate mineral with the chemical formula Ca₄Mn³⁺₂Al₂(Mn³⁺Mg)(SiO₄)₂(Si₃O₁₀)(V⁵⁺O₄)(OH)₆. It is named for its type locality, the Monte Alpe mine in Italy.^[2]

Alpeite
Alpeite crystals
General
Category	Minerals
Formula	Ca4Mn3+2Al2(Mn3+Mg)(SiO4)2(Si3O10)(V5+O4)(OH)6
IMA symbol	Apt
Identification
Color	Brownish red
Tenacity	Brittle
Mohs scale hardness	5.5-6
Luster	Vitreous, Silky
Streak	Beige
Diaphaneity	Transparent
Specific gravity	3.374