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By C. Denis George Abstract by Anna Kerrig Historical Aspects on the Early Discovery of the Pearl Cultivating Technique Japanese scientists, Nishikawa and Mise are typically recognized for discovering the technology that led to cultivating spherical pearls. C. Denis George was an Australian...

Measuring Pearl Quality Pearl quality and thus, the value of a pearl is measured according to a combination of several varied factors are: the type of pearl, the thickness of its nacre, its luster, the cleanliness and texture of its surface, its shape, its color, and its size. Because the...

Pearl Nucleus Defined A pearl nucleus is a bead or other object implanted into the gonad of a marine mollusk or into an existing pearl sac in the gonad or mantle of a freshwater mussel around which nacre deposition occurs. The Pearl Nucleus and Nucleation/Grafting Pearl farms vary depending on...

Pearl Surface in Pearl Grading The surface cleanliness of a cultured or natural pearl has a direct correlation to its value. A pearl can never, according to rules set forth by the FTC, be graded as "flawless", but the degree or percentage of inclusions or surface imperfections can be measured by...

Grading South Sea and Tahitian Pearls While there is no internationally recognized number or letter system for pearl grading, there are best-grading practices that are accepted and recognized by all professional pearl dealers within the industry. Understanding grading attributes and quality...

Pearl Treatments Defined Pearl treatments are defined as any action other than polishing which alters a pearl's appearance which may include: irradiation bleaching heating filling waxing drilling cutting faceting and working Pearl Treatments just after Harvesting After harvest, most pearls...

Mother-of-Pearl Defined Mother-of-Pearl (MOP for short) or Nacre (as it is also known) is the iridescent coating on the inside of some mollusk species which is composed of aragonite and calcite, both being calcium carbonate polymorphs. MOP also contains water and binding proteins secreted by...

Pearl Shapes Vary Widely Because pearls are natural organic gems created by a myriad of living organisms, they occur in a wide variety of shapes, many of which are quite unique and interesting. Also, cultured pearls tend to be rounder than natural pearls because (saltwater) cultured pearls...

Cultured and Natural Pearl Weight Descriptions Pearl weight is expressed in carats or grains when describing natural pearls, or kilograms, kan or momme when describing cultured pearls. When Is Pearl Weight Used Instead of Size? Most of the time, pearls are described primarily in terms of...

Pearl Size Is Measured in Millimeters A pearl's size is measured according to its diameter in millimeters. Sizes range from 1 millimeter or less, in the case of very tiny pearls, to as much as 20 millimeters (more than 3/4") for large South Sea pearls. The Average Pearl Size Today is 7.0-8.0...

Marine Pearl Farming Defined Pearl farming is the industry responsible for growing farm-raised pearl mollusks and producing cultured pearls. These cultured pearls make up nearly 100% of the pearls sold today. What Is Pearl Farming? Cultured pearls are grown on what are known as pearl farms...

The Pearl Harvest The pearl harvest is the pay-off for years of investment and arduous work. The harvest most-often happens during the winter months as the host mollusks' metabolism slows and nacre platelets become thinner as deposition decreases. This has proven to increase the luster upon...

The Proper Pearl Nucleus A pearl nucleus is usually made using freshwater mussel shells that has been cut and ground into a polished, spherical bead. Other nuclei do exist, these have been produced from other marine shells, such as from the large black and silver-lipped pearl oysters and from...

The 4000 Year History of Pearls Pearls have been prized and collected for more than four thousand years, giving them the title of the world's oldest gem. The Early History of Pearls Pearls have long been treasured and highly valued in many cultures throughout history. As far back as 2,300 BC...

Pearl History of Egypt We know that in ancient civilizations, long before recorded history, people adorned themselves with seashells and beads made from seashells. Therefore, it is not surprising that the earliest use of mother of pearl in jewelry occurred in Egypt, about 5,200 years ago. Mother...