Final answer:
Pearls, amber, and coral are formed in different ways and differ from most other gemstones. Pearls are formed by mollusks, amber is formed from fossilized resin, and coral is formed by marine animals called polyps.
Step-by-step explanation:
Pearls, amber, and coral are all formed in different ways and differ from most other gemstones.
Pearls are formed by mollusks, such as oysters, in response to an irritant like sand or grit. The mollusk forms a protective covering around the irritant, creating a pearl.
Amber is formed from the fossilized resin of ancient trees. The resin hardens over time and becomes amber. It is unique because it is not formed by geological processes but rather as a result of the preservation of organic material.
Coral is formed by tiny marine animals called polyps. These polyps secrete calcium carbonate and build upon each other, forming coral reefs over millions of years.