The cultivation of spherical Akoya pearls was originally discovered by William Saville-Kent in Western Austarlia more than 100 years ago. The insertion techniques were later patented by Dr. Tokishi Nishikawa of Japan and subsequently developed and used by Kokichi Mikimoto over the last century. These same techniques for nucleus insertion are still used today.
Japanese Akoya Pearl is a term often used as a misnomer to describe all cultured akoya pearls. Nowadays, akoya pearls are also grown in China, South Korea, Vietnam and Australia.
Pearl producers cultivate akoya pearls in a bivalve mollusk of the Pinctada genus. The primary species used in cultivation are the Pinctada fucata and the Pinctada chemnizti. The Pinctada fucata is native to the coastal waters of Japan, while the Pinctada chemnitzi is more prolific in Vietnam and along the coast of China. Today, most akoya pearl producers in both China and Japan cultivate with a hybridization of the two species.
Akoya pearls typically range in size from 2 to 11 mm, while the most common sizes fall between 7 and 9 mm. These sizes are small enough for daily wear and look proportionate on most women. The pearls are valued primarily for their size, shape, luster, color, and surface nacre. Large round pearls are always the most highly prized and small increases in diameter can increase valuations substantially. The quality and thickness of the nacre is reflected in the luster which along with the color is the most important factor affecting the beauty of the pearl. A smooth surface free of any blemishes is always desirable but uncommon in normal cultivation.
Akoya pearls predominately exhibit white body color with rosé, silver, or cream overtones. A rose overtone can range from pale pink to deeper, more saturated hues. This overtone deepens and enhances the pearl’s luster. Pairing these pearls with yellow gold will maximize this effect, making the pearls appear highly lustrous.
Silver overtones may also contain undertones of green or blue, giving the pearls an ethereal look. This overtone works equally well with both yellow and white gold and is best suited for women with dark hair and tan or olive complexions. The contrasting colors will make these pearls appear even larger to the eye.
A cream overtone, like rosé, enhances and deepens the pearl’s luster an the effect can be maximized by pairing the pearls with yellow gold. The finest cream overtones display flashes of violet, combining pink and blue to dazzling effect.
It’s all about luster.
Luster is the quantity and quality of light reflected from the pearl’s surface. The most valuable akoya pearls mirror recognizable objects and light reflections will appear crisp and sharply defined. Excellent luster displays sharp, crisply defined reflected light sources on the surface, and recognizable facial features will be visible on the pearl’s surface. A photograph of highly lustrous pearls could clearly show both the camera and the photographer in the image.
Pearls of very good luster will reflect sharply defined light sources off the surface, but some slight blurring or softening of the edges will be apparent. The face of the viewer may still be discernible on the surface but not all the details.
Good or Fair luster exhibits distinctly softer edges from the reflected light sources. Physical objects will appear heavily blurred on the pearl’s surfaces.