Aliettite

Aliettite is a complex phyllosilicate mineral of the smectite group with a formula of (Ca_0.2Mg₆(Si,Al)₈O₂₀(OH)₄·4H₂O) or [Mg₃Si₄O₁₀(OH)₂](Ca_0.5,Na)_0.33(Al,Mg,Fe)_2–3(Si,Al)₄O₁₀(OH)₂·n(H₂O).

It is a soft, colorless to pale yellow or green earthy mineral which crystallizes in the monoclinic system as minute tabular to platy crystals.