Here at Rohr Jewelers, pearls are definitely our specialty. We have one of the largest collections of cultured and natural pearls in the Midwest. Shop owner Sam Hill has a deep passion for pearls and travels to Japan annually to bring back a gorgeous array of pearls of all types. He also designs many pearl pieces featured in our store.
The pearl, a symbol of purity, virtue and modesty, is one of the most precious gems in jewelry. Technically known as "organic gems" because they are formed by mollusks, pearls have been harvested and worn for more than 4,000 years. The way they are harvested and cultured has changed over time, but pearls and pearl jewelry continue to be a classic.
A pearl is formed when an irritant, such as a parasite, becomes lodged in the shell of a mollusk. The mollusk deposits layers of a semi-translucent crystalline material called "nacre" around the intruder. where it builds up in layers like the rings of a tree. This process of building up can continue for years, resulting in a pearl. In nature, pearls take many years to develop and often have irregular shapes, ranging from slightly off-spherical to twisting, bulging shapes called "baroque." In any shape, natural pearls are rare and very costly.
Around the beginning of the 20th century, Kokichi Mikimoto discovered that if a sphere of material was placed into an oyster, and the oyster stimulated correctly, the oyster would coat the sphere with nacre, creating an almost perfectly round pearl. The longer the pearl remains in the oyster, the larger and more valuable the pearl becomes. These are called "cultured" pearls. Almost all pearls used in jewelry today are cultured pearls. Pearls are cultured all around the world by different types of oysters and mollusks. The type of oyster or mollusk, where they are raised, and environmental conditions, help determine the different sizes, colors, and characteristics of a cultured pearl.
Cultured pearls are rated on five different qualities:
- Luster: Luster is caused by light hitting and penetrating the pearls nacre. The light is reflected from different levels and angles created by the overlapping layers of nacre. This gives a pearl its brilliance and inner glow.
- Complexion: Pearl nacre is a matrix of calcium carbonate crystals. This matrix can be laid down in a perfectly uniform pattern over the entire pearl.
- Shape: Pearls starting with a round bead nucleus can still form many different shapes. These include Round, Semi-Round, Drop, Button, and Semi-Baroque.
- Color: Pearls come in a wide variety of colors naturally. The most popular are white, black, golden, pink, and different shades of these. Certain pearls also have secondary color or overtones.
- Size: Pearls come in all sizes, from under 1mm to over 20mm. Larger sizes of any variety of pearl will be the most valued.
South Sea Pearls
South Sea Pearls are among the largest, rarest, and most valuable of the cultivated pearls. They range in size from 9mm to 22mm. They come in two varieties, the White South Sea and the Golden South Sea, both of which are cultivated by the Pinctada Maxima oyster. The Pinctada Maxima is the largest type of saltwater oyster in the world and can grow as large as a dinner plate in size. South Sea Pearls have a unique satiny lustre, that comes from the fast growing nacre of the warm South Seas.