Mikimoto Pearl Fine Pins and Brooches
Kōkichi Mikimoto lived to be 96 and said he owed his good health to the two pearls hed swallowed every day since he was 20 years old. Mikimoto founded the Mikimoto Company and invented the cultured pearl industry, which creates real Akoya gems by introducing an irritant into the oyster that causes the animal to surround it with layers of nacre. Now Mikimoto Akoya gems are found in necklaces, pins, and brooches.
What is an Akoya gem?An Akoya gem is one that is harvested from the Akoya oyster Pinctada fucata martensii, which lives in salt water. Mikimoto natural gems are cultured, and they are usually round or off-round and white or off-white. The oysters are found in the waters off Japan but have also been found in the tropical seas.
How are the gems graded?There is no standardized grading system for pearls as there is for diamonds. Before they are attached to a brooch, they are judged by:
- Luster: This is the surface brilliancy of the gem. It should have strong and sharp light reflections, and there should be marked contrast between its bright and dark areas.
- Thickness of the nacre: Gems with a thick nacre have a good luster. Thin nacre tends to crack.
- Color: Mikimotos come in colors ranging from pink and white to shades of cream to gold. Besides the basic body color, these gems from nature also have overtones that can be seen under bright light and a rainbow-like play of multicolor called iridescence.
- Flaws: Like diamonds, these gems from nature can have flaws. These include large or small bumps, cracked nacre, welts, scratches, and nacre that has been rubbed off. They can also be discolored and have dull spots.
- Size: The diameter of a round Mikimoto is expressed in millimeters, with one millimeter being 1/2 of an inch.
- Weight: The weight of a Mikimoto Akoya pearl is expressed in grains, with one grain equaling 0.25 karat or 0.05 of a gram.
- Appearance: The way the gem looks in the piece of jewelry.
A Mikimoto brooch or pin may be made of:
- 14 karat yellow gold: This is pure gold alloyed with copper to retain the golden color. This type of gold is 58.3% gold.
- 18 carat yellow gold: 18K yellow gold is also alloyed with copper and is 75% pure gold.
- Sterling silver: A pin or brooch made of sterling silver is 92.5% silver and 7.5% copper alloy.
Diamonds, rubies, and emeralds sometimes join the Mikimoto gems in these pieces of jewelry. Diamonds are often channel set along the swirls of the gold or silver of the pin. Small square cut emeralds or round rubies are scattered among the Mikimoto jewels and the precious metal. Some jewelry may also include rhinestone.
How are these pieces of jewelry cared for?A Mikimoto pin or brooch should be kept in its own felt-lined compartment or bag. They should not be cleaned with a commercial jewelry cleaner, because too many of these cleaners contain ammonia. This jewelry should not be cleaned in an ultrasonic cleaner, steam cleaned, or cleaned with anything harsh or abrasive. Do not clean the piece with a soft-bristled toothbrush. Simply wipe it with a soft cloth, then put it away.
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