Chloritoid is a silicate mineral of metamorphic origin.

It is an iron magnesium manganese alumino-silicate hydroxide with formula (Fe, Mg, Mn)2Al4Si2O10(OH)4.

It occurs as greenish grey to black platy micaceous crystals and foliated masses.

Its Mohs hardness is 6.5, unusually high for a platy mineral, and it has a specific gravity of 3.52 to 3.57.

This article about a specific silicate mineral is a stub.