Cortez Pearl

Color:   Dark champagne to charcoal cultured pearls with iridescent purple, green, blue, gold, and peach overtones.
Gem Family:   Cortez Pearls® are rare saltwater cultured pearls from the rainbow-lipped Pteria sterna oyster, native to Mexico's Sea of Cortez. Pearls are organic gems, created when a mollusk covers a foreign object with beautiful layers of nacre, the mother of pearl. Cultured pearls are the result of the work of both man and mollusk: a skilled technician inserts a shell bead in the oyster to encourage the oyster to form a pearl. Pteria oysters are often used to produce mabe, or half-round pearls. Until now, pearls experts thought that the winged Pteria variety of oyster could not produce round cultured pearls.
Source:   These rare pearls are cultured in the waters of Bacochibampo Bay in the Sea of Cortez in Mexico, near the city of Guaymas, Mexico.
Clarity:   All Cortez Pearls® have a rich bright luster and striking iridescence.
Size Range:   8-10.5mm for earrings, rings and pendants. Some rare Cortez pearls are as large as 12mm!
Shapes Available:   Cortez Pearls® are available in semi-round, drop, and round shapes. Cultured Cortez Pearls® are much too rare to create strands.
Enhancement:   The shimmering iridescent natural colors of cultured Cortez Pearls® are not enhanced in any way. After they are removed from the shell, Cortez Pearls® are washed in water, soaked in mineral oil for six hours, and then dried.
Lore & History:   Spanish captain Fortun Jimenez admired the pearls he saw local people wearing when he visited what he called the "Sea of Pearls" in 1533. Natural pearls were harvested from these waters for the next 300 years, becoming an important export. Unfortunately, the construction of the Hoover Dam depleted nutrients in the Gulf of California, diminishing natural pearl production in the area. To protect the oysters, the government banned harvesting of natural oyster beds in 1939. The Monterrey Technical Institute in Guaymas began studying pearl culturing in 1993, producing the first experimental round pearls in 1996. Only 4,000 pearls are cultured in these waters each year, making them the rarest of cultured pearls. Only 30 percent of the production is round.
Toughness & Hardness:   Pearls have a hardness of 2.5 to 4 on the Mohs scale.
Care & Cleaning:   Pearls are organic and must be protected from chemicals and oils. Always put pearls on after you put on makeup, perfume, and hair products. Before putting your pearls away after wearing them, wipe them with a soft cloth to remove dust and oils. Store them in a cloth-lined box or pouch and keep them away from other jewelry, which might scratch them. Never put any pearls in an ultrasonic or steam cleaner.
Special Characteristics:   Cultured Cortez Pearls® can be distinguished from Tahitian cultured pearls, which many closely resemble, by the distinctive red fluorescence of Cortez Pearls® under long-wave ultraviolet. Cultured Cortez Pearls® also show a greater range of iridescent colors, including some shades that are not exhibited by Tahitian cultured pearls.