#5318 Boucheron Ring in yellow and white gold.
We all know that gold, in its natural form is a deep yellow color. That is true, regardless of where the gold is found or mined.
But sometimes, we come across a jewel that is of a variation of that deep yellow color. Why?
#4929 Mughal bangle in 22k yellow gold. 
Here are some things everyone thinking of buying antique jewelry should know.
Pure gold is referred to in the trade as 24k. That means that 24parts out of 24parts are pure, solid gold.
But most often,we see 18k, 14k, even 9k and variations.
What does this mean?
It means that the gold is mixed with other metals. Technically, the other metals, mixed with gold are called alloys. We don't need to bother with these technical terms, but we do need to understand why pure gold is mixed with other metals and what it means for us.
1. pure gold is very soft.
2. pure gold is very expensive.
3. pure gold is always that deep yellow color.
1. since gold is so soft, it is not practical when used alone. It will bend out of shape in half a moment, rendering the item useless. I just had a beautiful pair of earrings returned. They are made of 22k gold and the lady, while she loved them, said the wires simply bent when she tried to wear them. No use to anyone.
2. We all try to cut exorbitant costs. If 24k gold is wildly expensive, you can save by using a mixture of gold and other, cheaper metals.
3. Some people want their jewelry to match their taste for silver or red or green. Mixing yellow gold with certain metals, results in a change of color. For example, lots of copper mixed in with gold, imbues a rosy red tone and voila! rose or red gold!!
The amount of the other metals mixed with pure gold, changes the percent of gold and thus we get 22k, 18k etcetera.
#7104 Cartier earrings in red, white and yellow gold.
A most important aside: White gold was only developed for practical purposes around 1920. If someone tries to sell you an 'antique' made of white gold, be suspicious. Not to say that there was never, ever, white gold made earlier, but it is most unlikely. Almost impossible.
I once bought a very expensive pair of diamond hoop earrings set in silver, described as Georgian. I paid a lot because Georgian earrings like this are very rare and sought after. When we tested the metal, it turned out to be white gold and not silver. That means that there was no way the earrings were Georgian. True, white gold is more valuable than silver, but in this case, the value lay in the age and the age was disproved by the metal. At this point, the earrings were of absolutely no value to me.
The corny old phrases like 'all that glitters is not gold' are corny because they are true. There are other metals that might look like gold, but are not gold. There are metals covered in a thin layer of gold, but their value is significantly less than the value of pure gold.
Pay attention, know your basic facts and enjoy the most noble of metals.
#6766 red gold sautoir 
Questions: Please email antiques@brendaginsberg.com .
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