The three most popular colours of gold jewellery are yellow, white and rose.
Creating different colours involves mixing the pure 24K gold with other metals. The gold then becomes an alloy.
For example, 14K gold is an alloy consisting of fourteen parts pure gold and ten parts of other metals.
Pure gold is 24 Karat and yellow.
Gold in any other colour is an alloy.
An alloy is a mixture of metals. Alloys of gold, silver, copper, zinc, palladium and nickel create different hues of gold.
Alloys of gold and silver-coloured metals create white gold.
It is not a true white metal, it will always have a slight yellow hue.
The rhodium plate will eventually wear off leaving the piece of jewellery slightly yellow.
Re-plating the jewellery will return it to its white colour.
Over the last years rose gold has become more popular.
Also known as Pink Gold it has a very subtle colour which intensifies with age.
Copper and silver create the colour rose.
4% silver and 21% copper added to 75% gold typically makes 18K rose gold.
Rose Gold is available in 18K and 14K.
Other Types of Gold
Green gold is made of pure gold and pure silver and has a light sage green hue.
Adding zinc or nickel makes the gold more durable.
Green Gold is available in 18K and 14K.
Black gold isn’t created by the process of alloying, whereas the gold used is usually an alloy and not the pure 24K.
Methods used to create black gold are external coating, electroplating, heat treatment and controlled oxidation.
The combination of the hue of the original metal and the method used to colour it will determine how deep the final black of the gold becomes.
The most common technique for creating black gold is electroplating to add a layer known as a patina.
Electroplating with rhodium or ruthenium is most common, often starting from 18 karats white gold.
Although black gold jewellery isn’t everyone’s taste, it is undeniably eye-catching and unusual.
Black gold is often used by designers because the colour works well with diamonds and other gems.
Jewellery made from black gold is often more expensive than in other gold colours.
Purple gold is also known as amethyst or violet gold. It is made by mixing gold and aluminium at a fixed ratio.
Due to the gold content being almost 79%, purple gold qualifies to be referred to as 18K gold.
Blue gold is an intermetallic compound of gold and indium.