Basalt with Scoria and potential Olivine/Pyroxene inclusions

Physical Properties

Hardness: 5-6 (Mohs); Color: Dark grey to black with glassy/metallic luster in some areas; Texture: Vesicular (contains air bubbles/pores) and fine-grained; Crystal structure: Amorphous to microcrystalline; High specific gravity.

Formation & Geological History

Formed from the rapid cooling of magnesium-rich and iron-rich lava (basaltic) at or very near the Earth's surface. The 'holed' or vesicular texture is caused by gas bubbles escaping as the lava solidifies.

Uses & Applications

Used in construction as aggregate, road base, and railroad ballast. Highly vesicular specimens are used in landscaping, as BBQ grill stones, or for filtration.

Geological Facts

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.

Field Identification & Locations

Identify in the field by its dark color, heavy weight compared to other rocks of similar size, and presence of small holes (vesicles). It is commonly found near volcanic fields or oceanic crust outcroppings.

Identified on: 4/22/2026

Mode: Standard