fossil

Fossiliferous Limestone

Sedimentary rock containing Indeterminate Fossil remains (likely Crinoid stem or Bryozoan fragment)

AI-generated identification · may be incorrect

Hardness: 3-4 (Mohs); Color: Light gray to tan/buff; Luster: Dull, earthy; Crystal structure: Microcrystalline (calcite matrix); Cleavage: None (fractures irregularly); Specific gravity: 2.5-2.7

Hardness: 3-4 (Mohs)
Color: Light gray to tan/buff
Luster: Dull, earthy

Identified July 5, 2026More fossil →

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Physical properties

Hardness: 3-4 (Mohs); Color: Light gray to tan/buff; Luster: Dull, earthy; Crystal structure: Microcrystalline (calcite matrix); Cleavage: None (fractures irregularly); Specific gravity: 2.5-2.7

Formation & geological history

Formed in a shallow marine environment where calcium carbonate precipitated and buried organic remains. Over millions of years, pressure and chemical changes lithified the sediment into rock. Most common in Paleozoic era deposits.

Uses & applications

Primarily used for geological study, education, and as decorative garden stones. Larger deposits of limestone are used in construction, cement production, and as crushed stone for roads.

Geological facts

This specimen shows differential weathering, where the fossilized internal structure (possibly a segment of a crinoid stem or bryozoan) is slightly more resistant or differently mineralized than the surrounding matrix, causing it to stand out in relief.

Field identification & locations

Identify in the field by looking for grayish rocks with visible patterns, tubes, or shell shapes. It will fizz when exposed to a weak acid like vinegar (HCl test). Common in areas with ancient seabed exposure.