GemNotes

Desert Pearls of Scottsdale, Ariz., sells cultured abalone mabés grown in North American waters. While the colors are not as dramatic as the New Zealand natural and cultured mabés, current production continues to look promising, says Raymond Mason, president of DP.

Orient is the iridescent spectral colors seen coming from the surface as you rotate a pearl. Overtone is usually a smaller single color, different from the body color, which appears stationary as you move the pearl, as if someone had painted it onto the surface.

Pink rosés are the most popular. Colored pearls, such as goldens and blacks, gain value as the color becomes more obvious. Black pearls should have an iridescence of rainbow colors. A predominant blue or green overtone is most valued.

Colors can be enhanced by dyes and irradiation. Most saltwater cultured pearls are dyed or bleached. The conchiolin layer is whitened using hydrogen peroxide to even out the white body color. Pink and peach also are added to create more colorful body colors. Irradiation is used to make spotted pearls black, covering up uneven body color.

Matching. Matching is a value factor for all gems. If two or more match, they’re more valuable as a set then as single gems.

Pearl vocabulary. A pearl attached to the inside shell of a mollusk is called a blister pearl. Cultured blister pearls are created by attaching a round, half or fancy-shaped bead to the inside shell. The pearl, along with its attached shell backing, is cut away from the remainder of the shell.

Mabé is a Japanese term for half pearls. The attached bead is removed from the shell and a new shell back is cemented to the created pearl.

Majorica pearl is an imitation, or a bead that’s been coated.