Technonatural composite (often containing sedimentary/igneous aggregate)

Asphalt (Bituminous Concrete)

Asphaltum / Bitumen-Aggregate Matrix

Hardness: 1-3 (matrix), 5-7 (aggregate); Color: Dark charcoal to black (gray when weathered); Luster: Dull to greasy; Structure: Granular/clastic composite; Specific Gravity: 2.3 - 2.5

Hardness: 1-3 (matrix), 5-7 (aggregate)
Color: Dark charcoal to black (gray when weathered)
Luster: Dull to greasy

Identified March 23, 2026More technonatural composite (often containing sedimentary/igneous aggregate) →

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Physical properties

Hardness: 1-3 (matrix), 5-7 (aggregate); Color: Dark charcoal to black (gray when weathered); Luster: Dull to greasy; Structure: Granular/clastic composite; Specific Gravity: 2.3 - 2.5

Formation & geological history

Created by mixing mineral aggregate with bitumen (a heavy petroleum byproduct). While bitumen occurs naturally in tar pits (Late Pleistocene), most modern asphalt is an anthropogenic material replicating natural conglomerate processes.

Uses & applications

Primary material for road surfacing, parking lots, airport runways, and roofing shingles due to its durability and waterproof properties.

Geological facts

Naturally occurring asphalt has been used since ancient times for waterproofing boats and mummification in Egypt. The La Brea Tar Pits in Los Angeles are a world-famous natural source of asphalt.

Field identification & locations

Identify by its dark granular texture, slight petroleum smell when heated, and presence in paved areas. It is the most recycled material in the world by weight.

Other technonatural composite (often containing sedimentary/igneous aggregate) specimens

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Asphalt (Bituminous Pavement Bit)

Bitumen-bound aggregate (Petrochemical-bound composite)

sedimentary (anthropogenic/technogenic)

Asphalt (Bituminous Concrete)

Composite material (bitumen binder with mineral aggregate)

man-made rock (technosol)

Sandstone-based Concrete Fragment

Cementitious Composite with Sedimentary Aggregate

sedimentary (man-made/anthropogenic)

Asphalt Concrete (Bituminous Concrete)

Bituminous aggregate

sedimentary

Concrete

Anthropogenic Sedimentary Rock (Hydrated Calcium Silicate)

sedimentary (anthropogenic / man-made)

Terrazzo (with Marble and Granite fragments)

Cementitious or resinous composite containing Calcium Carbonate (CaCO3) and Silicates

sedimentary (man-made composite)