Asphalt Chunk (with aggregate)

Physical Properties

Hardness: variable (binder is soft, aggregate is 6-7); Color: black or dark grey with multicolored inclusions; Luster: dull to greasy; Structure: granular/porous; Cleavage: none; SG: 2.3-2.5

Formation & Geological History

Formed through industrial processes mixing bitumen (heavy petroleum) with aggregate (sand, gravel, crushed rock). Often found as debris near roadways or parking lots. Technically an 'anthropogenic sedimentary rock'.

Uses & Applications

Used globally for road construction, pavement, and roofing. Smaller chunks are waste material but can be recycled into new pavement.

Geological Facts

Naturally occurring asphalt (bitumen) has been used since ancient times for waterproofing boats and mummification, though this modern specimen is a refined petroleum product.

Field Identification & Locations

Identify by its distinct chemical/tar smell when heated or scratched, its sticky texture in high heat, and the presence of assorted crushed gravel bound by a black matrix. Commonly found near infrastructure.

Identified on: 4/13/2026

Mode: Standard