Prase quartz with actinolite inclusions

Physical Properties

Hardness: 7 (Mohs scale), Color: Leek-green to sage-green, Luster: Vitreous to waxy (when wet/polished), Crystal structure: Trigonal/Hexagonal, Specific gravity: 2.65

Formation & Geological History

Formed in low to medium-grade metamorphic rocks or hydrothermal veins where silica-rich fluids permeate through rocks containing iron/magnesium minerals. This specimen appears as a water-worn pebble.

Uses & Applications

Used primarily by lapidaries as a semi-precious gemstone, for cabochons, and as a popular collector's item due to the needle-like inclusions.

Geological Facts

The name 'Prase' is derived from the Greek word 'prasos' for leek, referencing its green color. The dark 'pepper' spots and lines inside are typically crystals of actinolite or hornblende.

Field Identification & Locations

Identify in the field by its characteristic leek-green translucency and the presence of dark needle-like inclusions. Common in coastal California and Europe.

Identified on: 5/3/2026

Mode: Standard