Basalt River Stone

Hardness: 6 (Mohs), Color: Charcoal grey to black, Luster: Dull/Matte, Crystal structure: Aphanitic (fine-grained), Texture: Smooth from water erosion.

Formed from the rapid cooling of magnesium-rich and iron-rich lava at or very near the Earth's surface. This specific specimen has been smoothed by fluvial (river) or glacial action.

Basalt is used in road base, concrete aggregate, railroad ballast, and as a natural material for stone massage or decorative landscaping.

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.

Identifiable by its dark color, heavy weight for its size, and lack of visible crystals. Commonly found in areas with past volcanic activity or in riverbeds where they have been transported.