sedimentary

Fossiliferous Limestone

Limestone with fossil bioclasts (Calcium Carbonate, CaCO3)

AI-generated identification · may be incorrect

Hardness: 3-4 (Mohs scale); Color: Gray to buff matrix with lighter cream-colored fossils; Luster: Dull to earthy; Structure: Fine-grained clastic matrix with visible shell fragments

Hardness: 3-4 (Mohs scale)
Color: Gray to buff matrix with lighter cream-colored fossils
Luster: Dull to earthy

Identified July 7, 2026More sedimentary →

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Physical properties

Hardness: 3-4 (Mohs scale); Color: Gray to buff matrix with lighter cream-colored fossils; Luster: Dull to earthy; Structure: Fine-grained clastic matrix with visible shell fragments

Formation & geological history

Formed in shallow, calm, warm marine waters from the accumulation of shell, coral, algal, and fecal debris. These fossils typically date from the Paleozoic or Mesozoic eras.

Uses & applications

Used primarily in construction (crushed stone, cement), as a soil conditioner in agriculture, and for decorative use in rock gardens. Small fossil specimens are popular for educational purposes.

Geological facts

The white patterns in this rock are fossilized remains, likely brachiopods, bivalves, or crinoids. Over 10% of all sedimentary rocks on Earth are limestones.

Field identification & locations

Identified by the presence of visible fossil remains in a soft, gray matrix that will react (fizz) when exposed to a weak acid like vinegar. Commonly found in former seabed locations and riverbeds.