18 - Shell limestone

Hello friends, Welcome to the Rock Repository at the Department of Geology, Shivaji Science College, Nagpur.

I am Shell Limestone, also known as shellstone or coquina, a sedimentary rock primarily composed of calcium carbonate derived from the accumulation of shells, shell fragments, and other organic debris. Within me, you'll find abundant shell fragments, ranging in size from microscopic to visible to the naked eye. These fragments often retain their original shapes and structures. Alongside shells, I may also contain other organic debris like coral fragments, foraminifera, algae, and sometimes traces of marine fauna. My appearance is characterized by a coquina texture, where shell fragments are loosely packed within a matrix of calcium carbonate cement. This loose arrangement contributes to my high porosity, with void spaces between the shell fragments. The degree of porosity can vary depending on factors such as cementation and compaction. I come into existence in shallow marine environments, thriving in places where calcium carbonate-secreting organisms flourish. These environments include coral reefs, lagoons, and coastal areas with calm and shallow waters. Within me, you'll often find abundant fossils, offering valuable insights into past marine ecosystems and paleoenvironmental conditions.

Throughout history, I've been utilized as a building material in regions where I am abundant. My unique texture and composition makes me particularly suitable for decorative purposes such as facades, columns, and ornamental carvings.

Thank you for visiting.