sedimentary

Conglomerate

Conglomerative Rudite (SiO2/CaCO3 matrix)

AI-generated identification · may be incorrect

Hardness: 6.5-7 (individual clasts) vs 2-5 (matrix); Color: Tan, brown, or gray matrix with multi-colored rounded pebbles; Luster: Dull/Earthy matrix; Structure: Clastic; Cleavage: None.

Hardness: 6
Luster: Dull/Earthy matrix

Identified May 24, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 (individual clasts) vs 2-5 (matrix); Color: Tan, brown, or gray matrix with multi-colored rounded pebbles; Luster: Dull/Earthy matrix; Structure: Clastic; Cleavage: None.

Formation & geological history

Formed in high-energy environments like fast-flowing rivers or beaches where rounded stones are deposited and later cemented by minerals like calcite or silica over millions of years.

Uses & applications

Primarily used in construction as a coarse aggregate for concrete, road base material, or as decorative building stone in landscaping and internal architecture.

Geological facts

Conglomerates are often dubbed 'pudding stones' due to their resemblance to fruit pudding; they indicate the presence of ancient water currents strong enough to move heavy pebbles.

Field identification & locations

Identify in the field by looking for rounded, water-worn pebbles larger than 2mm embedded in a finer-grained matrix. Commonly found in ancient riverbeds and alluvial fans.