DIAMOND STUDDED GOLD JEWELLERY MANUFACTURING UNIT

Jewellery is broadly defined as “ornament for the body”; it is ornament which can be worn and while this definition is frequently challenged and stretched by what are often referred to as “art jewellers” or “contemporary jewellers”, the majority of jewellery can be described as being wearable ornaments, often made from high-value materials such as precious metals and gemstones. The Jewellery industry – especially in Scotland – comprises largely of micro-businesses and small-to-medium sized enterprises (SMEs) with a few specialist larger manufacturers. The market divides into several sectors which largely correspond to the divisions in the business sizes: micro-businesses are likely to be involved in small-scale or individual production at a low-to-medium value level; SMEs are more likely to be involved in medium-to-high value production and the larger businesses are likely to be involved in production of high-turnover low-value work for the tourist industry. In terms of materials and processes, traditional jewellery production can be looked on as a form of micro-engineering, requiring the production of objects in metals with great accuracy. Most jewellery is produced from the precious metals – silver, gold, platinum and palladium – but may be produced in other materials such as pewter (especially for work for the tourist industry) or steel. These metal objects can then be connected – to make chain, for example – or be set with stones, enamelled or polished and in the very highest-grade of jewellery, multiple techniques may be used simultaneously. In order to create these pieces, a range of techniques are used, from the ultra-traditional cutting of metal using a saw, through soldering, into lost-wax casting and in more recent years 3D technologies such as laser-sintering and digital technologies such as laser-cutting have begun to play a part in the jewellery industry, a role that is set to expand as these technologies become more and more available. Jewellery is one trade which is still placed in the cottage industry category. However, the growing recognition of Indian workmanship by foreign luyers has result in bosting the export of cut and polished gems. The Gem and Jewellery Export Promotion Council was set up in 1966. This was a welcome stepas gem and jewellery has been recognised as an export-oriented industry. The council operating under the Union Commerce Ministry as a non profit service institution, has helped in the establishment of testing laboratories and training school at Jaipur and the Indian Gemmological Institute at Delhi. The council represent about 3,000 exporters of gems and jewellery. Gold has a characteristic pleasing colour but it assumes various colours, e.g: deep violet, ruby and purple, when reduced to a finely divided state by volatilization or colloid formation. It is the most extensible of all metals and can be reduced by hammering to a thickness of 0.00008. Impurities specially tellurium, bismuth, and lead reduce its malleability and ductility pure gold melts at 1063oC. Gold-copper alloys are harder more fusible and less malleable and ductile than pure gold. They have higher tensile strengths. The densities of these binary alloys are lower while those of triple alloys of gold, silver, and copper are higher. Gold silver alloys are soft, malleable, and ductile and their properties are intermediate between those of gold and silver. Gold iron alloys are hard but malleable & ductile. Gold and mercury form amalgams at ordinary temperatures. Mercury dissoves 0.11% of gold at 0oC and 0.126% at 100oC. Gold absorbs mercury forming a silver-white solid containing about 40% gold. On heating the mercury volatilizes leaving the gold residue. In addition to its use as a medium of international exchange and as a fiduciary to paper currency, about 5-10% of the world annual production is consumed in the useful arts. Its high specific gravity, resplendent lustre, pleasing colour, and non tarnishing quality have made it the most coveted metal for jewellery and comage since ancient times. The chief uses of gold are in comage, jewellery, dental alloys gold coating of base metals, and scientific instruments. The properties of gold which are valued in trade and industry are its pleasing colour and resistance to corrosion; malleability and ductility; low specific heat and latent heat of fusion; high electrical conductivity and reflective power & therepeutic effects of some of its salts. Alloys of gold and iron are used in France for making jewellery under the name of gris; the iron content varies between 15 and 20%. Aluminium forms a number of alloys with gold. One of them AuAl2 (22%Al) has a remarkable purple colour. The so called aluminium-gold is an alloy of copper with about 25% aluminum. It resembles gold in colour and it also slightly attached by nitric acid. Many recipes have been formulated for soldering gold. Many of them contain a considerable proportion of zinc with copper, silver and gold. In the prescence of copper, zinc does not cause brittleness, though the alloy formed is extremely hard and difficult to roll. Cadmium has been substituted for zinc in soldering alloys. The solders lose Zinc or cadmium by volatilization when heated and gradually become less fusible.