Aerinite

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 or compact masses and coatings. It has a dark, vitreous luster, a specific gravity of 2.48 and a Mohs hardness of 3.
It is a low-temperature hydrothermal phase occurring in zeolite facies alteration of dolerites. Associated minerals include prehnite, scolecite and mesolite.Its name comes from a Greek root “aerinos,” meaning “atmosphere” or “sky blue”. It was first described by Lasaulx (1876) from a specimen in the Wroclaw museum that was obtained in Aragon, Spain. In 1882, the geologist Luis Mariano Vidal found the mineral in situ in Caserras del Castillo, a locality that currently belongs to the municipality of Estopiñán del Castillo, in Huesca (Spain).