Aerinite (Ca₄(Al,Fe,Mg)₁₀Si₁₂O₃₅(OH)₁₂CO₃·12H₂O) is a bluish-purple inosilicate mineral. It crystallizes in the monoclinic system and occurs as fibrous masses and coatings. It has a dark, vitreous luster, a specific gravity of 2.48 and a Mohs hardness of 3.