sedimentary

Conglomerate

Conglomerate (clastic sedimentary rock)

Hardness: variable based on cement (typically 6-7 if siliceous); Color: mixed, earthy tones with dark inclusions; Luster: dull to earthy; Structure: clastic texture with rounded to sub-angular fragments; Cleavage: none; Specific Gravity: 2.6-2.9.

Hardness: variable based on cement (typically 6-7 if siliceous)
Color: mixed, earthy tones with dark inclusions
Luster: dull to earthy

Identified June 27, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the lithification of rounded gravel and clastic debris, typically in high-energy environments like riverbeds or alluvial fans. The specimen appears to contain various mineral grains cemented together by a fine-grained matrix.

Uses & applications

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

Geological facts

Conglomerates are often referred to as 'puddingstone' because the rounded clasts resemble raisins in a pudding. They reflect the high energy of the water that deposited the original gravel.

Field identification & locations

Identify by looking for distinct individual pebbles or grains larger than 2mm that are cemented together. It is commonly found in sedimentary basins and ancient river channels across the globe.

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