All the gold that will be worked into jewelry must be alloyed (mixed) with other metals in order to obtain sufficient strength. Gold is available in several different karat levels indicates how much gold as gold alloy contains. 24 carat is 100% pure gold, 18 carat is 75% gold.
The most common in the Swedish trade occurring 18K-gold alloy, "Swedish red gold", the gold content of 75%, 8-9% silver and copper 16-17%.
Gold can become discolored and it depends on the chemical and mechanical phenomena, including as it is affected by sulfides and chlorides in hudavsöndringar, sweat, saliva, etc. It is the proportion of copper and how your body affects the copper that makes the jewelry may be discolored.
This ring is not made by our own goldsmith, it is made by Wildcat in Germany.