Basalt (potential Glacial Erratic)

Hardness: 6 (Mohs); Color: Dark gray to black; Luster: Dull to sub-metallic; Texture: Fine-grained/Aphanitic; Specific Gravity: 2.8–3.0.

Formed from the rapid cooling of magnesium-rich and iron-rich lava at the surface. While the local bedrock of Northern KY/Cincinnati is sedimentary (Ordovician limestone), igneous rocks found here are typically glacial erratics transported by ice sheets from the Canadian Shield during the Pleistocene.

Commonly used as crushed stone for road base, concrete aggregate, and railroad ballast. Exceptionally durable for construction.

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

Identify by its dark color, heavy weight (density), and lack of visible crystals. Its presence in a sedimentary region like Northern Kentucky indicates glacial transport.