Calamites (Fossil)

Physical Properties

Hardness: 3-5 (depends on mineral replacement); Color: Tan, brown, or grey; Luster: Dull/Earthy; Structure: Internal cast displaying longitudinal ribs and nodes; Specific Gravity: varies with matrix.

Formation & Geological History

Formed through pith cast creation where prehistoric giant horsetails were buried in sediment during the Carboniferous period (approx. 300-360 million years ago).

Uses & Applications

Scientific study, educational museum displays, and private geological collections.

Geological Facts

Calamites were treelike plants that could reach heights of 30 meters; they are the ancestors of modern-day horsetails.

Field Identification & Locations

Identify by looking for parallel vertical ribbing and horizontal bamboo-like joints. Commonly found in coal-bearing shale and sandstone formations.

Identified on: 5/20/2026

Mode: Standard