Oolitic Limestone

Hardness: 3-4 (Mohs); Color: White, cream, or light tan; Luster: Dull to earthy; Texture: Granular (resembling fish roe); Cleavage: None (conchoidal fracture when fine-grained); Specific Gravity: 2.5-2.7

Formed in warm, shallow, wave-agitated marine waters. Small grains (ooids) form as calcium carbonate precipitates in concentric layers around a central nucleus, such as a shell fragment or sand grain. The provided coordinates near the Leitha Mountains/Vienna Basin are known for such Neogene carbonate deposits.

Used primarily in building construction (dimension stone), lime production, agriculture, and as a decorative stone in landscaping.

The term 'Oolite' comes from the Greek word 'oion' for egg, because it resembles fish roe. Portland stone, a famous building material used for St. Paul's Cathedral, is a prominent type of oolitic limestone.

Identify in the field by its distinct texture of tiny, spherical grains (ooids) visible to the naked eye or under a hand lens. It will react and fizz strongly with dilute hydrochloric acid. It is very common in the limestone areas of Eastern Austria.