gemstone

Pearl necklace

Pearl, primarily aragonite (CaCO₃) and conchiolin

AI-generated identification · may be incorrect

Organic gemstone with a smooth, lustrous surface and rounded shape; Mohs hardness about 2.5–4.5. The pictured pearls appear cream to white, but natural versus cultured and freshwater versus saltwater cannot be determined from the image.

Identified October 1, 2026More gemstone →

Explore Pearl necklace in the encyclopedia →

Identify your own rocks.

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

App Store Google Play

Physical properties

Formation & geological history

Pearls form in mollusks as layers of nacre around an irritant; cultured pearls are produced by human-assisted seeding. They are not classified as igneous, sedimentary, or metamorphic rocks.

Uses & applications

Used chiefly in jewelry and valued as a decorative gemstone.

Geological facts

Nacre is made of microscopic aragonite platelets bound by organic material, which creates pearl luster.

Field identification & locations

Pearls are distinguished by nacreous luster and characteristic surface texture; origin and quality require close inspection and often documentation. They are farmed worldwide, especially in China, Japan, and the South Pacific.