Jewelry is usually expensive. But the word “wealth” and “Beauty” has never been synonymous.
Different types of jewelry
Jewelleries vary depending on the material used, as well as characterized by the shape and jewelry design features, finishes. Smooth products can be engraved with a black, enamel, and others.
Personal jewelry includes earrings, rings, necklaces, bracelets, pendants, lockets, chains, necklaces.
Earrings – common type of jewelry; they are made of different materials, different shapes and configurations.
Clips – Earrings are made from inexpensive metals.
The rings are made of gold, silver and copper alloys. Rings of metal called a wedding, and the rings with inserts – decorative.
Beads – view of female ornaments. They are made of precious, semi-precious stones, glass, bones, wood, plastic. Beads nicely complement the clothing and have it in harmony. Beads are neck decoration in the form of elements of any shape, strung on a thread or wire-connected units.
The shape and design of the chain links are divided into armored, anchor, ribbon, fantasy, etc.
Neck decoration, decorative elements are fixed in its central part, called necklaces and jewelery. Decorative elements are fixed along its entire length – a necklace.
Pendants and medallions are neck adornments in the form of a suspension. Used in conjunction with a chain, a cord or ribbon.
Materials for jewelry
In the manufacture of the material distinguish gold, silver, platinum, cupro-nickel, nickel silver and other jewelry. Jewellery made of precious metals alloys are classified according to samples. Products from alloys of gold divided by the color shade on products from white, yellow, pink, green, blue and gold. According to a method of producing isolated cast, stamped, assembled jewelry; gold-plated, silver-plated, anodized, filigree, engraved, blackened. inlaid, etc . By the presence and type of inserts: products without inserts and with inlays of natural and artificial stones and other features.
Jewelry from precious metals
Precious metals include gold, silver, platinum, palladium, and others. These metals have a beautiful appearance, good gloss, resistance to chemicals and weathering, the required strength and low hardness. Advantages of precious metals led to their use as for the manufacture of jewelry material.
Gold is very soft and prone to broaching metal having a large mechanical strength. Gold bullion has a pure yellow color with a strong metallic luster.
Silver is a shiny white, very malleable and ductile metal. In nature, sometimes found in native form, but more often is a part of the lead-zinc ores.
Of all the metals silver has the highest reflectivity. 94% reflects the rays of light incident thereon. Good polishing and takes the best conductor of electricity and heat. Silver is very plastic so that is rolled into thin sheets up to 0.00025 mm thick and is drawn into fine wire. In pure form, silver is used in the jewelry industry for silvering articles of base metal.
For making silver jewelry alloys usually is used copper.
Platinum. This malleable metal of silver-white color with a grayish tinge and a metallic luster, color and luster somewhat resembling tin. In nature platinum is found almost exclusively in the native state. Its density is 21.4 g / cm.
In the production of jewelry in alloys platinum is used with copper and is used mainly as a frame for diamonds.
The palladium is a metal of silver-white color. It occurs in nature in the native state, together with platinum and is obtained from the platinum solution and its satellites. It has a large malleability and ductility: well rolled into thin sheets and stretched into a thin wire. Palladium is soluble in cold and hot nitric sulfuric acids, and also has the ability to absorb hydrogen.
Alloys of precious metals
Precious metals mostly have a high degree of ductility, toughness and ductility that applying them in pure form is impossible. So in jewelery, usually employed precious metal alloys are produced by fusing a precious metal or other non-ferrous metals.
Alloys of gold. Of the large number of alloys used in jewelery known gold alloys are very few.
For the manufacture of jewelry made of gold alloys are used mainly ternary alloys: gold, silver and copper; less binary alloys: gold, silver and copper gold. In some cases, (if necessary to obtain variously colored gold alloy) is used with a platinum gold alloy, cadmium, palladium and other metals. When alloying the gold with other metals, its alloys gives different shades: copper – red, cadmium – green, silver – palladium and platinum – white.
Alloys of gold (Au), silver (Ag) and copper (Cu), used in the jewelery industry, characterized by comparative strength. They have a beautiful yellow color, relatively well-forged, rolled and easily subjected to coining.
Red and other materials for jewelry
For non-ferrous metals include copper, nickel, zinc, cadmium, lead, aluminum, tin, chromium. In jewelery production they are used mostly in alloys with other metals.
Under the influence of humid air in the presence of carbon dioxide coated green copper coating. It is used for alloying of gold and silver, producing gold and silver solder, manufacturing mobile and other purposes.
Nickel is a metal silver-white color with a high gloss. In air, it does not tarnish.
Zinc is metal bluish-gray in color with a strong metallic luster. Apply zinc to produce some silver alloys and production of gold and silver solders. Alloys of copper and zinc are called brass.
Cadmium – a metal silver-white color with a bluish tint and metallic luster. It used for the manufacture of gold and silver alloys and solders.
Lead – very soft, ductile metal bluish-gray color with a high gloss. It is used for the manufacture of soft solders and mobile.
Aluminium – a metal silver-white color with a bluish tinge, very ductile, well rolled, stamped and forged. From aluminum manufactured various kinds of jewelery (necklaces, bracelets, brooches, etc.), Followed by anodizing, and coloring them under the color of gold and other colors.
Tin – malleable metal silver-white color. It is easily rolled into very thin leaves – tin foil, well drawn into wire. Included in the solders and bronze.
Chromium – metal beautiful silver-white color with a bluish tinge, featuring a large hardness.
Chromium uprights against the action of moist air, alkalis, nitric acid, most gases and organic acids, resists mechanical wear. These properties are used for electrolytic chromium coatings of different products, including watch cases.
Bronze, brass and red brass. Alloys of copper and tin, copper and copper-aluminum-silicon bronzes.
Brass or tombac – this alloys of copper with zinc (from 9 to 43%), sometimes with additives of lead, tin, iron, nickel, etc. brass color, the Cu content decreases it (at least 90%), gradually moving from copper-red to golden.
Nickel silver contains 65% copper, 15% nickel and 20% zinc. Resistant to corrosion. It is used for the manufacture of crockery and cutlery.
Melchior is an alloy containing 80% copper ‘and 20% nickel. The alloy has a high ductility, it can be easily processed in cold condition, suitable for deep stamping.
From German silver manufactures various crockery and cutlery and then silvering. It protects the product against corrosion and gives them a beautiful appearance. Melchior is also used as a frame for reinforcement of crystal products (flower vases, sugar bowls, candy, etc.).
Plastics are in increasing use in jewelery manufacture.
High mechanical strength, high light resistance, chemical resistance, high ductility, excellent paintability in any color, transparency (of many types), a successful imitation gems. Most importantly, the ability of quick and easy mass production of jewelry by pressing in dies (molds) with heating and a pressure, the distinctive properties of plastics.
Plastics are produced both from natural substances (cellulose, casein, etc.) and synthetic, obtained by chemical reactions (polyethylene, polystyrene, methacrylate, etc.).
For the manufacture of jewelry generally used polystyrene and acrylate.
Polystyrene density is 1.06 g / cm3, a hardness of Brinell is 18-21 kgf / mm2. Strong mineral acids and alkalis do not act on polystyrene. Products made of it are transparent, opaque, colorless and painted in different colors.
Acrylate (organic glass) is a transparent mass, refining the resultant esters of acrylic and methacrylic acids. It features high resistance to chemical attack. Painted in various colors.
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