Basalt River Stone

Hardness: 6 (Mohs scale), Color: Dark grey to black, Luster: Dull/Matte, Structure: Fine-grained (aphanitic), Specific Gravity: 2.8–3.0

Formed from the rapid cooling of magnesium-rich and iron-rich lava at or very near the Earth's surface. This specimen has been rounded by fluvial erosion in a river or coastal environment.

Commonly used as decorative landscaping stones, massage stones, and in construction as aggregate for roads or concrete.

Basalt is the most common rock type in the Earth's crust and makes up most of the ocean floor. It is also found on the Moon and Mars.

Identify by its heavy weight, dark color, and lack of visible crystals. Commonly found in riverbeds or on beaches near volcanic regions.