A pearl is a hard, glistening object produced within the soft tissue of a living shelled mollusk or another animal, such as fossil conulariids. Just like the shell of a mollusk, a pearl is composed of calcium carbonate in minute crystalline form, deposited in concentric layers; the ideal pearl is round and smooth, but many other shapes, known as baroque pearls, can occur. The finest quality of natural pearls have been valued as gemstones and objects of beauty for many centuries; because of this, pearl has become a metaphor for something rare, fine and valuable. The most valuable pearls occur spontaneously in the wild, but are rare; these wild pearls are referred to as natural pearls. Cultured or farmed pearls from pearl oysters and freshwater mussels make up the majority of those sold. Imitation pearls are widely sold in inexpensive jewelry, but the quality of their iridescence is very poor and is distinguished from that of genuine pearls. Pearls have been harvested and cultivated for use in jewelry, but in the past were used to adorn clothing.

They have been crushed and used in cosmetics and paint formulations. Whether wild or cultured, gem-quality pearls are always nacreous and iridescent, like the interior of the shell that produces them; however all species of shelled mollusks are capable of producing pearls of lesser shine or less spherical shape. Although these may be legitimately referred to as "pearls" by gemological labs and under U. S. Federal Trade Commission rules, are formed in the same way, most of them have no value except as curiosities; the English word pearl comes from the French perle from the Latin perna meaning leg, after the ham- or mutton leg-shaped bivalve. All shelled mollusks can, by natural processes, produce some kind of "pearl" when an irritating microscopic object becomes trapped within its mantle folds, but the great majority of these "pearls" are not valued as gemstones. Nacreous pearls, the best-known and most commercially significant, are produced by two groups of molluskan bivalves or clams. A nacreous pearl is made from layers of nacre, by the same living process as is used in the secretion of the mother of pearl which lines the shell.

Natural pearls, formed without human intervention, are rare. Many hundreds of pearl oysters or mussels must be gathered and opened, thus killed, to find one wild pearl. Cultured pearls are formed in pearl farms. One family of nacreous pearl bivalves – the pearl oyster – lives in the sea, while the other – a different group of bivalves – lives in freshwater. Saltwater pearls can grow in several species of marine pearl oysters in the family Pteriidae. Freshwater pearls grow within certain species of freshwater mussels in the order Unionida, the families Unionidae and Margaritiferidae; the unique luster of pearls depends upon the reflection and diffraction of light from the translucent layers. The thinner and more numerous the layers in the pearl, the finer the luster; the iridescence that pearls display is caused by the overlapping of successive layers, which breaks up light falling on the surface. In addition, pearls can be dyed yellow, blue, pink, purple, or black; the best pearls have a metallic mirror-like luster.

Because pearls are made of calcium carbonate, they can be dissolved in vinegar. Calcium carbonate is susceptible to a weak acid solution because the crystals react with the acetic acid in the vinegar to form calcium acetate and carbon dioxide. Freshwater and saltwater pearls may sometimes look quite similar, but they come from different sources. Freshwater pearls form in various species of freshwater mussels, family Unionidae, which live in lakes, rivers and other bodies of fresh water; these freshwater pearl mussels occur not only in hotter climates, but in colder more temperate areas such as Scotland. Most freshwater cultured pearls sold. Saltwater pearls grow within family Pteriidae, which live in oceans. Saltwater pearl oysters are cultivated in protected lagoons or volcanic atolls. Pearls are formed inside the shell of certain mollusks as a defense mechanism against a threatening irritant such as a parasite inside the shell, or an attack from outside that injures the mantle tissue; the mollusk creates a pearl sac to seal off the irritation.

Pearls are thus the result of an immune response analogous in the human body to the capture of an antigen by a phagocyte. The mollusk's mantle deposits layers of calcium carbonate in the form of the mineral aragonite or a mixture of aragonite and calcite held together by an organic horn-like compound called conchiolin; the combination of aragonite and conchiolin is called nacre. The held belief that a grain of sand acts as the irritant is in fact the case. Typical stimuli include organic material, parasites, or damage that displaces mantle tissue to another part of the mollusk's body; these small particles or organisms gain entry when the shell valves are open for feeding or respiration. In cultured pearls, the irritant is typically

Don Gosen

Don Gosen is a State Farm Insurance Agent, co-owner of a brewery, a former Republican member of the Missouri House of Representatives. He had represented the 101st district, which includes parts of Chesterfield, Wildwood and Clarkson Valley, since 2011. Don Gosen's father was a teacher and his mother was a homemaker. Don Gosen was raised in attended Hermann High School, he received a BSBA and MBA from the University of Missouri. He went to work for Boone County National Bank in Columbia as a commercial loan officer, he moved to upstate New York to continue his career in insurance. For a small time he worked for several breweries, he received Brewing Certificate from the Institute of Brewing and Distilling in London, United Kingdom, he received his brewing microbiology schooling from the Lallemand Institute in Montreal, Canada, he moved back to St. Louis where helped found the Tin Mill Brewing Company and where he has been a State Farm insurance agent for twenty years. Gosen is a member of the West County Chamber of Commerce, a member of the Wildwood Business Association, a member of the Master Brewers Association of St Louis, a member and former president of the Wildwood Area Lion's Club.

He lives in Chesterfield, with his wife and three children, attends the Living Word United Methodist Church in Wildwood. In 2010, Don Gosen ran to represent the 84th district in the Missouri House of Representatives, he started his campaign in 2009 and was unopposed in both the Republican primary and the general election. He was reelected to represent the 101st district in 2012. On February 17, 2016 Representative Gosen resigned, after he was asked to resign by Speaker of the House Todd Richardson the evening prior. Reasons the representative gave for resignation included having "personal issues". While the reasons for his resignation were unclear at the time, Gosen acknowledged it was due to an extramarital affair that began in 2014. In July 2016, Gosen announced that he was considering re-entering politics, considering offices at the city and county level. Elections Insurance Policy Utilities General Laws Official Missouri House of Representatives profile Campaign Finance Information


Distribuciones Froiz, S. A. is a Spanish supermarket chain based in Galicia. It operates in the Spanish regions of Galicia, Castile and León, Castilla-La Mancha, Madrid and in Northern Portugal; the company was founded in Pontevedra in 1970 by Magín Alfredo Froiz and remains a family-run business. In October 2014, Froiz bought rival supermarket Supermercados Moldes becoming the third biggest supermarket chain in Galicia. Froiz's operations are divided into four formats, differentiated by size and the range of products sold. Tandy or Merca Mas is the name given to Froiz's franchised convenience stores. Froiz is the owner of the cycling team Grupo Deportivo Supermercados Froiz and the main sponsor of the Óscar Pereiro Foundation cycling team. List of supermarket chains in Spain OfficialOfficial website Supermercados Froiz on Facebook Supermercados Froiz on Twitter FinancialDistribuciones Froiz S. A. — Hoover's