Gold is a metal with a bright yellow colour and is the main material used in jewellery making. People have loved it from ancient times to the present day because of its unique properties, rarity and beauty. Pure gold is also called Venetian gold, a name that refers to the Venetian coins, which were made exclusively of solid gold. For gold we also use the word "malama" referring not only to jewellery, but also to quality, e.g. for a person we say "he has a malama heart", as well as "he has a heart of gold". Gold is extremely expensive, because of the enormous difficulties and costs of mining and processing, but also because of supply and demand.
The special features of gold
Some of the special characteristics of gold are the following:
- Does not oxidize (does not rust),
- Can be forged very easily,
- Has a unique colour and shine,
- It is non-toxic and does not cause allergies,
- It is edible!
- It is very soft and flexible (even a gram of gold can be made into a very thin plate and giving us a square meter of gold leaf).
The colour of gold and alloys
Yellow gold is the most common, but gold today is also available in a wide range of colours. Because it is soft enough to work with, alloys are formed with impurities of gold and other metals in order to make more durable objects and to make it more affordable.
An alloy is the union of two or more metals to form a new material. Depending on the impurities, the alloy acquires the corresponding colour. Yellow gold alloys contain mainly bronze, white gold alloys contain silver and palladium, and pink gold alloys contain copper. Other attempts to produce alloys of other colours are currently under investigation.
The measurement of gold in carats
The carat (K) is a unit of gold content and should not be confused with the carat (CT) which is the unit of weight of precious stones.
The purity of gold in an alloy with other metals is determined by its carat. 24 carats is the maximum limit which means that the gold has not been mixed with other metals. At 18 carats, therefore, we have 75% gold and 25% other metals, such as bronze, copper or silver. In 14 carat jewellery we have respectively 58.33% gold and 41.67% other alloys.
Each piece of jewellery is engraved with the purity of its metals expressed per thousand units. That is, an 18-carat jewel, which consists of 75% pure gold, is stamped with 750 degrees.