sedimentary
Calamites Fossill (Lepidodendrales)
Calamites sp. (Family Calamitaceae)
Hardness: 3-4 (matrix usually siltstone/shale); Color: Grey, tan, or black; Luster: Dull/Earthy; Structure: Internal cast or external impression showing longitudinal ribs and nodes; Specific gravity: 2.5-2.8
- Hardness
- 3-4 (matrix usually siltstone/shale)
- Color
- Grey, tan, or black
- Luster
- Dull/Earthy
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Physical properties
Hardness: 3-4 (matrix usually siltstone/shale); Color: Grey, tan, or black; Luster: Dull/Earthy; Structure: Internal cast or external impression showing longitudinal ribs and nodes; Specific gravity: 2.5-2.8
Formation & geological history
Formed during the Carboniferous period (approx. 360 to 300 million years ago) in swampy, equatorial wetland environments where these giant horsetail-like trees grew.
Uses & applications
Scientific study, educational museum displays, and moderate value geological collecting.
Geological facts
Calamites grew to heights of over 30 to 50 meters. They were major contributors to the formation of coal beds across North America and Europe.
Field identification & locations
Identify by looking for parallel vertical ribbing and horizontal joints (nodes). Commonly found in coal mine tailings and sedimentary outcrops in the Appalachian and Illinois Basins.
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