sedimentary

Asphalt (Aggregate)

Bituminous macadam / Concrete Aggregate

AI-generated identification · may be incorrect

Hardness: 3-5 (varies by aggregate type); Color: Black to dark gray; Luster: Dull to oily/resinous; Crystal structure: Amorphous to microcrystalline; Cleavage: None/unpredictable; Specific gravity: 2.3-2.5

Hardness: 3-5 (varies by aggregate type)
Color: Black to dark gray
Luster: Dull to oily/resinous

Identified March 22, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the industrial mixing of crushed sedimentary rocks (like limestone or sandstone) with bitumen, a highly viscous petroleum product. The geological age of the base components ranges from millions of years, though the composite material is relatively modern.

Uses & applications

Primary use in road construction, pavement, roofing shingles, and waterproofing materials. It is the world's most recycled material.

Geological facts

Natural asphalt lakes exist (like La Brea Tar Pits), but most modern asphalt is a byproduct of the oil refining process. It behaves as a non-Newtonian fluid in very high temperatures.

Field identification & locations

Identify in the field by its dark black color, granular texture, and distinctive hydrocarbon odor when heated. It is ubiquitous in urban environments like the street pictured.