Gold
The Basics
Gold is a rare metallic element with a melting point of 1064 degrees centigrade and a boiling point of 2808 degrees centigrade. Its chemical symbol, Au, is short for the Latin word for gold, 'Aurum', which literally means 'Glowing Dawn'. The ability of gold to efficiently transfer heat and electricity is bettered only by copper and silver, making it indispensable in electronics, for semi-conductors and connectors in computer technology.
Gold in Jewellery
The proportion of gold in jewellery is measured on the carat (or karat) scale. The word carat comes from the carob seed, which was originally used to balance scales in Oriental bazaars. Pure gold is designated 24 carat, which compares with the "fineness" by which bar gold is defined. Pure gold is used in countries where jewellery is purchased as much for investment as it is for adornment, but it tends to be vulnerable to scratching. Elsewhere, it is usually mixed, or alloyed, with other metals. Not only do they harden it, but influence the colour; white shades are achieved by alloying gold with silver, nickel or palladium; yellow and red alloys contain mainly copper. A harder alloy is made by adding nickel or a tiny percentage of titanium.
The most widely used alloys for jewellery in Europe are 18 and 14 carat, although 9 carat is popular in the UK. In the United States 14 carat predominates, with some 10 carat. In the Middle East, India and South East Asia, jewellery is traditionally 22 carat (sometimes even 23 carat). In China, Hong Kong and some other parts of Asia, "chuk kam" or pure gold jewellery of 990 fineness (almost 24 carat) is popular. See below table which compares caratage with the "fineness" by which bar gold is defined.
|
Pure gold Gold alloys |
Caratage |
Fineness |
% Gold |
|
24 |
1000 |
100 | |
|
22 |
916.7 |
91.67 | |
|
18 |
750 |
75 | |
|
14 |
583.3 |
58.3 | |
|
10 |
416.7 |
41.67 | |
|
9 |
375 |
37.5 |
In many countries the law requires that every item of gold jewellery is clearly stamped with its caratage. This is often controlled through hallmarking, a system which originated in London at Goldsmiths' Hall in the 14th century.
History of Gold Jewellery
The earliest gold jewellery dates from the Sumer civilisation in between the Tigris and Euphrates rivers in southern Iraq around 3000 BC. A major archeological find of early jewellery was in the Royal tombs of Ur, in Mesopotamia, dated to around 2,600 BC where gold articles made by lost wax casting included a wild ass on the rein ring of a chariot. A beautifully modelled bull cast in gold dating to 2,300 BC was found in the Caucasus in eastern Europe. In Egypt, gold jewellery and have been found in Pharoah's tombs dating to around 1500 BC and later.
However, recent discoveries suggest that goldsmithing first began on the shores of the Black Sea, in the land that is today Bulgaria as artefacts found are thought to date before 3000BC
Articles displaying various techniques such as repousse, chain- making, alloying and casting have been found in ancient Egyptian tombs, with the best known examples coming from the treasures of King Tutankhamun who died in 1352 BC. The Minoans on Crete produced the first known cable chain, still very popular today, and the Etruscans in Italy had developed granulation, whereby items are decorated with tiny granules of gold, by the 7th century BC.
The Italian Renaissance period coincided with the discoveries of the New World sources of gold, and wealthy Italian patrons encouraged goldsmiths as they did painters and sculptors. The Spanish acquisition of South American gold, however, was achieved at the expense of the ancient heritage of Pre-Columbian goldsmiths. These craftsmen were producing exquisite items as early as 1200 BC and their art reached its zenith during the Chimu civilisation from the 12th to the I5th centuries AD, halted only by the mass looting and slaughter by the "conquistadors".
Italy has become jewellery manufacturer to the world, using over 400 tonnes of gold annually, more than 2/3 of it for export. Factories often housing several hundred ma- chines that "knit" gold wire into chain flourish in the towns of Arezzo, Bassano del Grappa and Vicenza. Important new centres emerged in the early 1990s, notably in Hong Kong, Singapore, Malaysia and Thailand, catering particularly for the rapidly growing market for chukka am (pure gold) jewellery in China, which requires several hundred tonnes a year. In Japan jewellery fabrication for the domestic market has become a major industry, using around 100 tonnes a year.
The most famous piece of gold is considered by many to be the face mask of the boy-king of Egypt (1361-1352 BC), Tutankhamun discovered in his tomb in 1922 by Howard Carter. The piece is usually displayed at Cairo Museum.