Basalt with Amygdules

Physical Properties

Hardness: 6 (Mohs scale), Color: Dark grey to black matrix with brownish-pink/white inclusions, Luster: Dull/Earthy, Crystal Structure: Aphanitic (fine-grained), Specific Gravity: 2.8 - 3.0

Formation & Geological History

Formed from extrusive volcanic activity where gas bubbles (vesicles) were later filled with secondary minerals like zeolites, calcite, or quartz during hydrothermal processes.

Uses & Applications

Commonly used in road construction, landscape decoration, and geological education. High-quality specimens with colorful vugs are used in lapidary arts.

Geological Facts

This rock represents an ancient gas-rich lava flow. The spots you see are 'frozen bubbles' that have been turned into solid mineral pockets over millions of years.

Field Identification & Locations

Identify in the field by its heavy weight (high density), dark matrix, and characteristic 'spotted' appearance of secondary mineral fillings. Found in major volcanic provinces globally.

Identified on: 4/14/2026

Mode: Standard