Conglomerate

Physical Properties

Hardness: 2-7 (variable based on clasts/cement); Color: Brown, tan, with green algae/moss coating; Luster: Dull/Earthy; Structure: Clastic with rounded grains/pebbles; Cleavage: None

Formation & Geological History

Formed through the lithification of rounded gravel and pebbles in high-energy environments like riverbeds or alluvial fans. This specimen shows significant weathering and biological growth (algae/moss).

Uses & Applications

Used primarily in the construction industry as coarse aggregate, building stone, and occasionally for decorative landscaping.

Geological Facts

Conglomerates are often referred to as 'puddingstone' in certain regions. Because they consist of rounded pebbles, they indicate that the sediment was transported a long distance by water before being deposited.

Field Identification & Locations

Identify by looking for distinct, water-worn rounded pebbles cemented within a finer-grained matrix. Often found in old river drainage basins or coastal areas.

Identified on: 4/25/2026

Mode: Standard