sedimentary

Calamites Fossil in Sandstone

Calamites (Genus) in Lithic Sandstone

AI-generated identification · may be incorrect

Hardness: 6-7 (sandstone matrix); Color: Tan, beige, grey; Luster: Dull/Earthy; Structure: Clastic matrix with a carbonaceous or cast impression showing longitudinal ribs and joints.

Hardness: 6-7 (sandstone matrix)
Color: Tan, beige, grey
Luster: Dull/Earthy

Identified June 1, 2026More sedimentary →

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Physical properties

Hardness: 6-7 (sandstone matrix); Color: Tan, beige, grey; Luster: Dull/Earthy; Structure: Clastic matrix with a carbonaceous or cast impression showing longitudinal ribs and joints.

Formation & geological history

Formed during the Carboniferous period (approx. 300-360 million years ago) in swampy, deltaic environments where giant horsetail-like plants were buried in river silt and sand.

Uses & applications

Scientific study, educational specimens, and geological collecting.

Geological facts

Calamites were treelike plants related to modern horsetails that could grow up to 30 meters (100 feet) tall. They are major contributors to the coal seams found in the Northern Hemisphere.

Field identification & locations

Identify by the parallel vertical ridges (ribbing) and nodes on the fossilized stem. Commonly found in coal-bearing regions such as the Appalachian Mountains, UK, and Germany.