Volcanic Scoria (Metate)

Hardness of 5 to 6 on the Mohs scale, dark brown to black or reddish-gray color, dull luster, highly vesicular (porous) texture with numerous gas cavities, specific gravity around 2.7 to 3.0.

Formed from gas-rich mafic lava that cools rapidly at the Earth's surface, allowing expanding gas bubbles to create a vesicular texture. Formed during volcanic eruptions throughout geological history, often from basaltic cinder cones.

Historically used as a grinding stone (metate) for food preparation such as milling grains and corn. Also used in lightweight aggregate concrete, landscaping, barbecue grills, and occasionally as an abrasive stone.

This specific artifact shows a shaped, concave metate used alongside a mano (handstone) for grinding, serving as a fundamental domestic tool in many ancient and indigenous cultures around the world, particularly in Mesoamerica.

Easily identified by its extremely vesicular, sponge-like or bubbly appearance and heavy basaltic composition. Found worldwide in volcanic regions, especially near ancient archaeological sites where basaltic lava flows were accessible.