Mineral
Estilbita
NaCa₂Al₅Si₁₃O₃₆·14H₂O · Silicatos (Zeolitas)
Stilbite is a zeolite typical of the basalts of the Deccan Traps, where it fills amygdaloidal cavities alongside heulandite, apophyllite and chabazite. It is a late-stage, cavity-filling secondary mineral. Its crystals form fans or bow-ties with a pearly lustre, a result of its platy habit and hydrated structure. In well-preserved specimens like this, the faces show slight curvature and a warm tone ranging from cream to peach, a hallmark of the Pashan stilbites.
Etymology
From the Greek "stilbein", to shine, in reference to its characteristic pearly lustre.