
sedimentary
Asphalt aggregate (crushed stone in bitumen)
Artificial composite; predominantly crushed granite, basalt, limestone, and/or recycled aggregate bound by bitumen
AI-generated identification · may be incorrectDark gray, rough, granular, and noncrystalline overall; individual fragments vary in hardness (about Mohs 3–7), color, luster, and density. The black matrix is petroleum-derived bitumen rather than a natural mineral.
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Physical properties
Dark gray, rough, granular, and noncrystalline overall; individual fragments vary in hardness (about Mohs 3–7), color, luster, and density. The black matrix is petroleum-derived bitumen rather than a natural mineral.
Formation & geological history
Human-processed paving material made by heating and mixing mineral aggregate with asphalt binder, then compacting it; it has no single geological age, though the aggregate may derive from ancient bedrock.
Uses & applications
Used extensively for roads, driveways, parking areas, and roofing; it has no typical jewelry or collector value.
Geological facts
The visible angular rock chips are aggregate, while the dark continuous material is asphalt binder. Weathering commonly exposes aggregate and produces lighter gray, crumbly surfaces.
Field identification & locations
Identify it by the dense, irregular mixture of angular stones embedded in a black, slightly glossy or matte binder; it differs from natural conglomerate because the matrix is asphalt and the texture is engineered. Common worldwide in paved surfaces.
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