Alloying 18k gold to red gold?

Jewelry Discussion
1

I have about 20 grams of 18k gold that I would like to turn into
rose or red gold. What would I need to do this and with what
proportions?

Thanks,
Richard

2

Hello Richard,

If you work on an estimate that your gold contains 17.5% silver
(3.5grams) and 7.5% (1.5grams) Copper, (bear in mind that this may not
be the case and there are many different recipes) You would need to
add enough gold and copper to the mix to reduce the percentage of
silver to about 5% minimum to turn the gold pink.

This means that you would have to increase the gold and copper
content proportionally so that you have 70 grams of pink gold.

70g of 18K pink
75% AU =52.5g
20% CU = 14g
5% AG = 3.5g

Is it worth adding that amount of gold just to save on wasting 20
grams? rather keep the yellow and mix a new batch of red as the true
red gold contains no silver at all and it is impossible to alloy a
mix that already contains silver.

Regards,
Gwen

3

20 gr of what gold color? Which carat does it need to be ?

4

Well Richard. If you had pure gold no problem. just add copper. if
you have 18k yellow then adding more copper will give it more of a
rosy tent and depending on what you want the final kt. To be as to
how much rose color you will get, but it will not be as rosy as if
you started with pure gold. The silver alloy washes out the copper
rosy tent in the alloy. Yellow gold is usually copper And silver as
the main alloys.

Vernon Wilson

5

That is what I was afraid of. I don’t know the silver content. I
will just leave it as yellow gold, too many variables to work with.

If I start from scratch, with 24k yellow what percentage of copper
do I add? and is it just copper?

Thanks

6

Hi again,

Good call -

For red, alloy entirely with copper (pure) so,

25% CU
75% Au

Cheers,
Gwen