Apophyllite

Apophyllite is a group of phyllosilicate minerals. The name apophyllite is derived from the Greek words apo ("from") and phyllon ("leaf"), referencing its tendency to flake off in layers when heated. Apophyllite is a common mineral in the vesicles of basaltic lava flows and can also be found in hydrothermal veins and as a secondary mineral in various rock types.

Crystals of apophyllite are typically found in tetragonal form, exhibiting pseudomorphic cubic or equant habits. They are often transparent to translucent and can vary in color, appearing colorless, white, green, yellow, or even pink. Apophyllite is known for its vitreous to pearly luster. It is relatively soft, with a Mohs hardness of 4.5 to 5, and has a specific gravity of around 2.3 to 2.4.

Common associated minerals include zeolites, calcite, and analcime. Notable locations for apophyllite crystal discovery include India, Brazil, Germany, and the United States. Apophyllite is not typically used for commercial purposes but is valued by mineral collectors for its aesthetic appeal and crystal forms. In some metaphysical circles, apophyllite is believed to possess healing properties and is used for meditation and spiritual practices.