Prehnite

Prehnite is a mineral from the phyllosilicate group, composed of hydrous calcium and aluminum silicate (Ca₂Al₂Si₃O₁₀(OH)₂). It generally occurs as botryoidal, globular, or tabular crystal aggregates, with colors ranging from pale green to yellowish-green, but can also be white, colorless, or yellowish.

It primarily forms in cavities within volcanic rocks, often associated with zeolites, epidote, calcite, or apophyllite. Its slightly translucent surfaces and pearly to vitreous luster give it a soft and characteristic appearance.