The Many Colors of Gold

The Many Colors of Gold

You likely know about many different
colors of gold such as yellow white or rose, but you probably haven’t realized
just how many different shades of gold there are. One way the color of gold is
changed is by mixing it with other metals this mixture of metals is
referred to as an alloy. Most gold jewelry is formed from alloys. Only 24
karat gold is pure. 24 karats means the gold is 24 out of 24
parts gold or a hundred percent. Where 18 karat gold will be 18 out of 24
parts gold or 75%. So what are the other metals that are added to make different
colors of gold? Many alloys contain copper or silver which can make the
jewelry harder since pure gold is surprisingly soft. This graph shows various ratios of copper silver or gold and what color they would appear for example a
ratio of one part silver to three parts gold by weight will make a greenish or
greenish yellow alloy of gold this is commonly referred to as electrum using
other ratios can also produce yellow gold, white gold, red gold, or rose gold.
Other colors can also be made from alloys with different metals for example
Spain gold is an alloy of aluminum and gold and grey gold can be made with
palladium in gold. Gold can also be reacted with aluminium gallium or indium
to form compounds that are sometimes referred to as blue gold or purple gold
but these are compounds and not alloys. They are much more brittle than real
gold and are very rarely used in jewelry. One last method of producing
different colors of gold is by forming oxides of different alloys. By causing
the outer layer of certain alloys to corrode, shades of either black or blue
gold can be produced, but this color is only forming on the outermost layer. so
which color is your favorite and if you’d like to see more videos on metals
and alloys let me know in the comments below. Thanks for watching.


  1. I would like to see a more in deep video on this, especially the effect of gold on the tarnish resistance of the alloy.

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