For those who do not know, we classify the different alloys of gold according to their purity of gold. The unit of reference, which has not changed for centuries, is the carat and includes 24 graduations.
Gold is usually at 9, 14, 18, 22 karat jewelry but also at 24-carat gold for monetary gold only (at this purity of gold is too malleable).
Alloys, it is the different mixtures of metals used to make a mixture at the desired color and/or properties. Contrary to popular belief, there is not a single alloy for each label like pink gold, white gold, yellow gold, etc … (https://en.wikipedia.org/wiki/List_of_alloys#Alloys_of_gold), these are just completely arbitrary categories to classify the different alloys. If companies have never stopped refining their recipes alloy, we can still draw broad trends.
In the video below you can see how the 18k simple yellow gold by melting the various precious metals. The artisan simply brings the mixture at the highest melting temperature (that of copper at 1085 ° C), once a homogeneous alloy is allowed to cool in the mold and it’s done. We get a bar containing 75% gold, 12.5% silver, 12.5% copper.
This is a basic alloy however. Large companies like Legor specialized in creating alloy at large-scale Those alloys are necessarily more complicated, with elements present in quantities so small that it is not conceivable to manufacture alloy such small quantities.