sedimentary
Conglomerate
Clastic Sedimentary Conglomerate (SiO2, CaCO3 dominant)
Hardness: 3-7 (variable); Color: Tan, brown, and grey with rounded embedded clasts; Luster: Dull/Earthy; Crystal structure: Amorphous/microcrystalline matrix; Cleavage: None; Specific Gravity: 2.1-2.6
- Hardness
- 3-7 (variable)
- Color
- Tan, brown, and grey with rounded embedded clasts
- Luster
- Dull/Earthy
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Physical properties
Hardness: 3-7 (variable); Color: Tan, brown, and grey with rounded embedded clasts; Luster: Dull/Earthy; Crystal structure: Amorphous/microcrystalline matrix; Cleavage: None; Specific Gravity: 2.1-2.6
Formation & geological history
Formed in high-energy environments like river beds, alluvial fans, or beaches where water movement rounds rock fragments which are later cemented by minerals like calcite or silica.
Uses & applications
Primarily used in construction as a coarse aggregate in concrete, as a fill material, and occasionally as a decorative architectural stone.
Geological facts
Conglomerate is often called a 'pudding stone' because it looks like bits of fruit in a pudding. It indicates the presence of an ancient high-speed water source.
Field identification & locations
Identify by the presence of rounded pebbles (clasts) larger than 2mm embedded in a finer-grained matrix. Commonly found near active or ancient sedimentary basins.
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