Basalt with Quartz Veins

Physical Properties

Hardness: 6-7 (Mohs); Color: Dark grey or charcoal base with white/cream veins; Luster: Dull/earthy matrix with glassy veins; Structure: Microcrystalline; Specific Gravity: 2.8-3.0

Formation & Geological History

Formed from the rapid cooling of magnesium-rich and iron-rich lava at the surface. The white veins represent later hydrothermal activity where silica-rich fluids filled cooling cracks or fractures.

Uses & Applications

Commonly used as decorative garden stones, in construction aggregate (road base), and as 'worry stones' or beach pebbles for collectors.

Geological Facts

These are often called 'Wishing Stones' if a single white line encircles the entire rock. They are shaped into smooth ovals by tidal action and wave erosion over many years.

Field Identification & Locations

Identify by the high-contrast white crystalline lines cutting through a dark, fine-grained matrix. Often found on volcanic coastlines or in glacial till.

Identified on: 4/24/2026

Mode: Standard