Saltwater pearls are created naturally in response to a threatening and/or irritating entity randomly entering the shell of a marine mollusk, usually an oyster, after which the intruder is coated with layers of organic matter to seal it off from the vulnerable, soft-bodied organism. This process occurs relatively rarely in nature, and randomly-encountered natural pearls have therefore always been extremely scarce. Historically, the most desirable and valuable natural specimens were “oriental pearls” from the Middle East’s Arabian Gulf and Red Sea, as well as the Gulf of Mannar between India and Sri Lanka.

However, in 1916 a “culturing” process was patented off Japan’s south coast, whereby the above chain of events could be initiated via human intervention to produce whitish Akoya pearls. These techniques were then employed in warmer tropical waters to produce larger varieties such as blackish Tahitian pearls and white, silver or gold South Sea pearls.