What does the term "organic" refer to in the context of gemstones?

In the context of gemstones, the term "organic" specifically refers to stones that are produced by, or derived from, living organisms. This category includes materials like pearls, amber, and coral, which all originate from biological processes. For instance, pearls are formed within the shells of certain mollusks as a defense mechanism against irritants, while amber is fossilized tree resin. These organic materials differ fundamentally from minerals, which are classified as inorganic and formed through geological processes over long periods of time.

Understanding this distinction is crucial for gemology, as organic gemstones can have unique properties, origins, and value factors that differ from inorganically formed stones. Other options discuss general categories that do not capture the specific link to living organisms that defines organic gemstones. For example, naturally occurring stones may include minerals, while synthetically made stones obviously do not have any organic origin.