sedimentary

Fossiliferous Limestone (Murchisonia/Gastropod Limestone)

Biogenic Limestone (Calcium Carbonate, CaCO3)

Hardness: 3 (Mohs scale), Color: Gray to brownish-gray with white/off-white fossil inclusions, Luster: Dull to earthy, Structure: Fine-grained matrix with fossilized shell fragments. Microcrystalline texture.

Identified June 24, 2026More sedimentary →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Formed in shallow marine environments through the accumulation of calcium carbonate and marine organism remains. These specimens from the Burgenland/Vienna Basin region (47.7°N, 16.5°E) are likely Leithakalk (Leitha Limestone) from the Miocene epoch, roughly 10-16 million years old.

Uses & applications

Primarily used as a decorative building stone locally (St. Margarethen quarry nearby), in the production of lime, cement, and as a popular subject for local fossil collectors.

Geological facts

The region near Eisenstadt and Lake Neusiedl is famous for the Leitha Limestone, which was used to build many of Vienna's most famous historic buildings, including St. Stephen's Cathedral and the State Opera.

Field identification & locations

Identify in the field by looking for circular or spiral white patterns (cross-sections of gastropod shells) in a gray matrix. It will react and bubble (effervesce) when exposed to a weak acid like vinegar due to its calcite content.

Other sedimentary specimens

See all

Sandstone or Siltstone

Arenite (if sandstone)

Sedimentary

Chert Breccia

Brecciated Chert (Microcrystalline Silica)

sedimentary

Sandstone

Arenite (primarily SiO2)

sedimentary

Sandstone Grain

Clastic Sedimentary Rock Grain (SiO2 dominated)

sedimentary

Shale or Slaty Mudstone

Argillaceous sedimentary rock

sedimentary

Sandstone

Arenite

sedimentary