Gold has to be one of the most significant materials in history, both culturally and economically. A malleable and dense material that, together with copper, silver, lead, tin, iron and mercury, was alone in the known metals family for 7,700 years. Without exception, it is the only metal in the metals family that is chemically stable, all the others react with oxygen and other elements to corrode.
Gold has never really been an industrial designer’s material. Naturally, jewellery designers use gold all the time, but outside of jewellery any reference to gold in design can be seen as intentionally kitsch or perhaps seen as overdoing it slightly. As a benchmark of value and luxury and a status symbol, gold is unique in the sense that it has not been replaced by more contemporary synthetic materials, such as carbon fibre or titanium, two materials that always crop up in luxury brands. Use it even in the smallest quantity and it instantly creates an air of luxury for a product. The purity of gold is measured in carats. Twenty-four carat is pure gold, 18 carat refers to a purity that is 18 parts gold out of 24, or 75 per cent pure gold.
Gold is extremely malleable and can easily be beaten into incredible, translucently thin sheets. An example of this is seen in the fact that just 28 grams (1 oz) of gold can be worked into a flat leaf covering 16 square metres (172 square feet); one of the reasons it has been so well worked and applied in jewellery for thousands of years.
Image: Gold Pill by Tobia Wong
•Extremely malleable
•Corrosion resistant
•Does not oxidize
•Biocompatible
•Capable of good surface finish
•High thermal conductivity
•High electrical conductor
•Recyclable
Sources
China, followed by Australia and the US, is the biggest producer of gold. Other major producers include Indonesia, Peru, Russia and Ghana.
Cost
£33,245 ($52,000) per kg.
Sustainability issues
Apart from its rarity in nature, the main issues with gold appear to be in mining it and ensuring mines and mining countries have ethical policies. A significant proportion of mining of gold takes place in developing countries and the impact of mining is significant in these fragile economies. Safe working conditions, production of toxic waste, non-use of mines not in protected areas and dumping of mining waste are all considerations for sourcing gold ethically. One example is the use of highly toxic mercury to extract gold from its ore. Here, the gold is picked up by the mercury, which is then eventually boiled off to leave the gold. On a positive note, 28 g (1 oz) of gold can cover 92 square metres (1000 square feet) of glass, in this instance it can be energy efficient in reducing cooling costs in a building, due to its ability to deflect the sun. At the end of 1999 the World Gold Council estimated that all the gold that had ever been mined would create a cube 19.35 metres (63 feet) on each side, or enough to fill 125 double-decker London buses.
Production
As with other metals, gold can be cast using a variety of techniques. It can also be used for gilding and to electroplate. It can be beaten, woven into thread and used to make gold leaf.
Typical applications
Apart from jewellery and surface decoration, gold is used as an alloy in dentistry for dental restorations. The electronics industry use goldplated contacts and connectors in applications where silver and copper are not as tarnish resistant. It is used in biomedical devices and nanotechnology, which exploit its corrosion resistance. It is also used as coatings for glazing to reduce the transmission of heat.
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–Extremely malleable –Excellent conductor of heat and electricity –Biocompatible –Corrosion resistant –Recyclable |
–Rarity and expense limits use –Environmental/ethical issues around mining |