sedimentary

Conglomerate

Conglomerate (Clastic sedimentary rock)

AI-generated identification · may be incorrect

Hardness: 6.5-7 (variable); Color: Grey, brown, or tan matrix with white quartz inclusions; Luster: Dull to vitreous; Structure: Clastic with rounded clasts; Cleavage: None

Hardness: 6
Color: Grey, brown, or tan matrix with white quartz inclusions
Luster: Dull to vitreous

Identified June 5, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 (variable); Color: Grey, brown, or tan matrix with white quartz inclusions; Luster: Dull to vitreous; Structure: Clastic with rounded clasts; Cleavage: None

Formation & geological history

Formed through the lithification of rounded gravel and boulders, typically in high-energy environments like riverbeds, alluvial fans, or beaches. These sediments are cemented together over millions of years by minerals like silica or calcite.

Uses & applications

Used primarily in the construction industry as coarse aggregate for concrete and road building. Occasionally used as a decorative stone in architecture or landscaping.

Geological facts

Conglomerates are often referred to as 'puddingstone' because they resemble a fruit pudding. They are significant indicators of past water flow and energy levels in ancient geological environments.

Field identification & locations

Identify in the field by looking for rounded pebbles or cobbles 'glued' into a finer matrix. Often found in ancient river systems or glacial deposits. Common globally.