tsilaisite
Tsilaisite is a mineral with the chemical formula NaCaMgSi6O15(OH)·H2O. It is a rare silicate mineral that was first discovered in the Tsilaizina pegmatite in the Malagasy Republic (now Madagascar). The mineral was named after the locality where it was found. Tsilaisite belongs to the amphibole group of minerals, characterized by its double-chain silicate structure. Its physical properties include a vitreous luster and a hardness of approximately 5 on the Mohs scale. It typically appears as prismatic crystals and can range in color from colorless to pale yellow or green.
The geological occurrence of tsilaisite is primarily associated with complex pegmatites, which are igneous rocks characterized