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Process of Casting silver Jewellery
A two-step process, investment casting, produces small, complex shapes. Most castings, especially large ones, are made in sand molds. Permanent metal molds are used to make many small, simple parts; shell molding gives greater accuracy for a large volume of semi precision parts.Molten silver is poured into the cavity and allowed to solidify. Sand, mixed with a binder to hold it together, is pressed around a wooden pattern that leaves a cavity in the sand. Wax or plastic replicas of the parts are molded in accurate metal molds. Top of the line casting equipments are utilized to produce the silver jewellery. When the whole mold is heated, the replica melts, leaving behind a cavity into which silver is poured.
Pearls come in a variety of colors and shapes
A high quality pearl will have a lustrous, shiny surface, strong reflections, and a good contrast between its light and dark areas. Pearls come in a variety of colors. That colors are white, gray, black and yellow. The shapes of pearls can be round, baroque, symmetrical, or irregular. The most exquisite and expensive pearls are the sphere-like round pearls.But still your pearls should have minimal blemishes on the surface such as pits, cracks, or discoloration. Necklaces with pearls can have single or double strands. The single strands usually have larger, more expensive pearls than the double strands. Pearls that appear completely flawless are usually fakes. Authentic pearl earrings should match in size and their look and feel.
Gemstones are identified by gemologists
Gemstones are identified by gemologists. The first characteristic a gemologist uses to identify a gemstone is its chemical composition. Gems are characterized in terms of refractive index, dispersion, specific gravity, hardness, cleavage, fracture, and luster. They may exhibit pleochroism or double refraction. Who describe gems and their characteristics using technical terminology specific to the field of gemology.Next, many gems are crystals which are classified by their crystal system such as cubic or trigonal or monoclinic. They may have luminescence and a distinctive absorption spectrum. For example, diamonds are made of carbon (C) and rubies of aluminium oxide (Al2O3). Another term used is habit, the form the gem is usually found in. For example diamonds, which have a cubic crystal system, are often found as octahedrons.
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