Class : Sulfates, chromates, molybdates
    Subclass : Hydrated sulfates
    Crystal system : Trigonal
    Chemistry : Ca₆Fe₂(SO₄)₂[B(OH)₄](OH)₁₂ 25H₂O
    Rarity : Very rare

Sturmanite is an hydrated sulfate of the ettringite group, which forms prismatic hexagonal bipyramidal crystals of yellow to yellow-green color, rarely brown. It owes its name to B. Darko Sturman, Assistant Curator of the Royal Ontario Museum in Toronto, Canada. It is found in the oxidation zone of a manganese deposit. It is a mineral with a complex structure, [B(OH)₄] groups partially substituting for SO₄ groups. It is a very rare mineral sought after by the most informed collectors.

This mineral is not present in the French underground.

Twinning probable but not described.

No fake recorded for this species. It is a very difficult mineral to differentiate from ettringite without chemical analysis, some specimens of ettringite may be labeled sturmanite and vice versa. Some crystals may exhibit mixtures and be zoned with parts of ettringite composition and other sturmanite.