Organic gems are organic substances formed by biological processes that meet the requirements of gemstone craftsmanship and cannot be synthesized artificially. Common gems on the market include pearls, Alsophila spinulosa, amber, ivory, etc. Although cultured pearls have some artificial factors, the culture process is similar to natural ones, so they are also classified as natural.

The main difference between organic gemstones and inorganic gemstones is that organic gemstones must be related to animal and plant activities and are subject to the laws of biophysics and biocrystallization mineralogy.

Coral

Coral is red and white, and is a fossil of seabed coelenterates. It is divided into red coral [expensive coral], white coral (mostly used for bonsai crafts), blue coral (almost extinct now), black coral (expensive), and gold coral (with clear spots on the surface).