Celadonite

Celadonite is a mineral from the mica group, composed of a hydrous potassium, iron, magnesium, and aluminum silicate. Ranging from light green to emerald green or olive green in color, it primarily forms in cavities of volcanic rocks, where it lines the walls with thin crusts or small crystalline aggregates.

Often associated with zeolites, calcite, or apophyllite, celadonite is valued for its natural green hues, which highlight the crystals of other minerals, particularly in the famous deposits of Maharashtra (India).