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Q&As since 1989


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Karat purity vs. thickness in gold plating

Q. I WANT TO KNOW HOW MANY MICRONS IS 23 KARAT IN GOLD PLATING?

OLA CHARLES
CHARLES BIJOUX TRADING,WATCHES AND JEWELRY - PRETORIA, SOUTH AFRICA
2006

A. Hi Ola,
You are asking a question that relates apples to oranges. Micron refers to gold thickness as plated, 23k refers to gold purity plated. Simply put, you have 23 out of 24 parts of gold purity. One part is an alloy added to the plating solution to achieve a certain color and hardness. Hope this helps you.

Mark Baker
process engineer - Malone, New York
2006

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Gold plating purity -- should lower karat cost less?

March 18, 2020

Q. Hi,

I'm a custom jewelry buyer in Hanoi, Vietnam.
We're interested in Gold plated jewelry (in 14K and 18K).

I want to know when electroplated gold is in certain thickness, say 1 micon, what is the purity of gold layer?

Some plating houses inform me the 14k and 18k is just color reference and has no meaning to the purity, and the purity of both 14k and 18k gold layer would be 98.5% gold, and therefore the price of plating both 14k and 18k is the same.
Is it true?

If so, is there any way to plate with desired purity of gold? (e.g. 14k and 18k) so that the price of plating cost is different?

Thanks,

Kevin Han
buyer - Hanoi, Vietnam

A. 14K is 58% gold. 18K is 64% gold, so 18K costs more than 14K. However the gold plating is so very thin that the cost difference per piece is negligible. And it may be that it is neither actually 14K nor 18K. More likely the plater is referring to color, where one piece looks to be the color of 14K and the other the color of 18K. Jeffrey Holmes, CEF Spartanburg, South Carolina March 18, 2020 March 19, 2020 Q. Sorry if I made you confused. thickness is 1micron~3micron. My question is, if we plate the same thickness to two item, can we make different karat plating? say 14k and 18k? And approx. how much plating price difference in the two? (I try to search online, they say for jewelry purpose, it should be "hard gold" and the purity should be about 99.5%.) Thank you! Kevin Kevin Han [returning] buyer - Hanoi, Vietnam