Pearls

Natural or real pearls are made by oysters and other mollusks.

Cultured pearls are also made by mollusks, but with human intervention; that is, an irritant introduced into the shell causes a pearl to grow.

Imitation pearls are man-made.

Black pearls can occur naturally or be man-made.

Seed pearls are small pearls that measure approximately two millimeters or less.

A pearl's value is based on its size, usually stated in millimeters, and the coating of nacre (pearl material), which gives it iridescence.

Guidelines:

1. Identify whether the pearls are natural, cultured, or imitation.
2. Provide the measurements of the gemstone. Describe the size and the level of nacre (pearl material).

Source:

• All That Glitters...The Jive on jewellery, August 1998, Federal Trade Commission (FTC)
• Guides for the jewellery, Precious Metals, and Pewter Industries, FTC
• In the Loupe: Advertising Diamonds, Gemstones, and Pearls, August 1998, FTC