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A pearl is a hard, rounded object produced by certain mollusks, primarily oysters, and which is cultivated or harvested for jewellery.
Pearls are formed inside the shell of certain bivalve mollusks; as a response to an irritating object inside the shell, the mollusk will deposit layers of calcium carbonate (
The unique luster of pearls depends upon the reflection and refraction of light from the translucent layers and is finer in proportion as the layers are thinner and more numerous. The iridescence which some pearls display is caused by the overlapping of successive layers, which breaks up light falling on the surface. Pearls are usually white, sometimes with a creamy or pinkish tinge, but may be tinted with yellow, green, blue, brown, or black. Black pearls are often highly valued because of their rarity.
Almost all pearls used for jewelry nowadays are cultured by planting a core into Pearl Oysters. The pearls are usually harvested two years after the planting. This mariculture process was first developed by Kokichi MikimotoKokichi Mikimoto ( March 10, 1858 September 21, 1954) is the Japanese inventor of the cultured pearl. Born as the first son of a noodle shop owner in Toba, Mie prefecture he left school at the age of 13 selling vegetables to support the family. Seeing the from JapanJapan (, Nippon/Nihon literally "the origin of the sun") is a country in East Asia situated on a chain of islands east of the Asian continent on the western edge of the Pacific Ocean. The largest of these islands are, from north to south, Hokkaido , Honsh, who was granted a patentA patent is a set of exclusive rights granted by a government to an inventor or applicant for a limited amount of time (normally 20 years from the filing date). The term "patent" originates from the term patere which means to lay open (to public inspectio for the process in 1896Events January 4 Utah is admitted as the 45th U. January 5 An Austrian newspaper reports that Wilhelm Rontgen discovered a type of radiation later known as X-rays. January 12 H. Smith takes the first X-ray photograph. January 18 The X-ray machine is exhib. The original Japanese cultured pearls are produced by a species of small oysters no bigger than 6 to 7 cm in size, hence Japanese pearls larger than 10mm in diameter are extremely rare and highly priced. In the past couple of decades, cultured pearls have been produced with larger oysters in the south PacificFor other meanings of pacific see pacific (disambiguation). The Pacific Ocean (from the Spanish Pacifico meaning peaceful is the world's largest body of water. It encompasses a third of the Earth's surface, having an area of 179. 7 million kmē (69. 4 mill and Indian OceanThe Indian Ocean is the third-largest body of water in the world, covering about 20% of the Earth's water surface. It is bounded on the north by southern Asia (the Indian Sub-continent); on the west by the Arabian Peninsula and Africa; on the east by the. South Sea pearls are characterized by their large size and silvery color, 14mm in diameter are not uncommon. AustraliaAustralia is the sixth-largest country in the world (geographically), the only one to occupy an entire continent, and the largest in the region of Australasia. Australia includes the island of Tasmania, which is an Australian State. Its neighbouring count is one of the most important sources of South Sea pearls.
Recently (in the 1990sCenturies: 19th century 20th century 21st century Decades: 1940s 1950s 1960s 1970s 1980s 1990s 2000s 2010s 2020s 2030s 2040s Years: Events and trends Computers, technology Explosive growth of the Internet; decrease in the cost of computers and other techn), the Japanese also invested in producing cultured pearls with freshwater mussel s in the region of Shanghai, China, and Fiji. Freshwater pearls are characterized by the reflection of rainbow color in the luster. Cultured pearls are also being produced using abalone.
The value of the pearls in jewelry is determined by a combination of the luster, color, size, lack of surface flaw and symmetry that are appropriate for the type of pearl under consideration. Amongst those attributes, luster is the most important differentiator of pearl quality according to jewelers. For example, a small Japanese pearl is often valued higher than a bigger south sea pearl. Large perfectly round pearls are rare and highly valued and reserved for making rings. Teardrop shaped pearls are often used in pendants. Irregular shaped pearls are often used in necklaces.
See also baroque pearl, mother of pearl, Broome.