Rock Identifier
Green Apophyllite (Fluorapophyllite-(K), KCa4(Si8O20)(F,OH)·8H2O) — mineral
mineral

Green Apophyllite

Fluorapophyllite-(K), KCa4(Si8O20)(F,OH)·8H2O

Hardness: 4.5-5 (Mohs scale); Color: Pale green to seafoam green; Luster: Pearly to vitreous; Crystal Structure: Tetragonal; Cleavage: Perfect on {001}; Specific Gravity: 2.3-2.4

Hardness
4
Color
Pale green to seafoam green
Luster
Pearly to vitreous
Identified More mineral

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Physical properties

Hardness: 4.5-5 (Mohs scale); Color: Pale green to seafoam green; Luster: Pearly to vitreous; Crystal Structure: Tetragonal; Cleavage: Perfect on {001}; Specific Gravity: 2.3-2.4

Formation & geological history

Formed through secondary hydrothermal processes, typically as a late-stage mineral in cavities of basalt (amygdules) and other volcanic rocks. Most high-quality specimens date to the Cretaceous or early Tertiary periods.

Uses & applications

Primarily used as a collector’s specimen. It is valued by mineralogists for its high water content and unique crystal habits. Occasionally used in holistic healing practices.

Geological facts

The name comes from the Greek words 'apo' and 'phyllon', meaning 'to flake off,' referring to how the mineral exfoliates when heated. Specifically, the green variety is prized for its rarity compared to clear or white varieties.

Field identification & locations

Identify in the field by its distinct four-sided 'blocky' or 'pyramidal' crystals, pearly cleavage planes, and lack of reaction to HCl. Widely found in the Deccan Traps of India (specifically the Pune and Nasik districts).