What is aragonite?

Aragonite is indeed a crystalline form of calcium carbonate, which sets it apart from calcite, another form of calcium carbonate. It is commonly found in various natural environments, including marine settings, where it forms the mineral component of nacre, also known as mother of pearl, which is produced by certain mollusks. This material has a layered structure and contributes to the lustrous appearance of pearls. The significance of aragonite extends beyond its composition; it plays an essential role in geological and biological processes.

The other options—organic gemstones, synthetic stones, and opaque quartz—do not describe aragonite accurately. Understanding the unique properties and formation of aragonite helps in recognizing its importance in both geological contexts and in the study of gemstones.