Now that Walker Goldsmiths has explored Sterling Silver let us explore a rather more complex set of Alloys, those referred to as “karat gold”. Just like sterling we have the stamping laws to contend with. The law was designed to appeal to the vanity of artists so that if you put your name or trademark on a piece of jewelry you MUST stamp the karat quality of the gold. The gold content of each karat is set by law with a .01% allowable error. Stamping laws vary from country to country so I will just discuss the ones that are common in the United States. The two most common karats in the US are 14K and 10K with some higher end pieces being made of 18K.
I should explain the difference between karats and carats. In the US the symbol for karat which is the amount of gold in an alloy is K. Carat is the weight of a stone, for instance, a 1 Ct. Diamond. Pure gold (.999fine) is 24 karat gold so to find the gold content of 14K we divide 14 by 24 which gives us the decimal for the fineness or gold content of the alloy 14K is .583 fine. This means that there is 58.3 percent gold in the alloy. Now you are wondering of what does the rest consist? Legally it does not matter what the rest of the alloy is, but it matters when you want a color or some specific properties. Years ago my dear friend Doug Phillips gave me a book called Gold Alloys Their Manufacture & Applications by George E. Gee published in 1929. This is a fascinating read and it also has lists of gold alloys, the amounts of different metal used in each one and the uses and properties. Here is one called 14 Karat Rich Fine Yellow Gold Alloy; Fine gold .583, fine silver .150, and pure copper .267. The rule is that the gold content stays constant, the silver, copper and other metals can be varied depending on the use and color desired.
I make a 14K red gold that has no silver in it so it looks like copper but does not tarnish, so it is .583 gold and .414 copper. If you look at Black hills gold you will see green gold (more silver) and pink gold (more copper) to make the flowers and leaves. White gold is commonly made with nickel in it; 3% nickel in an alloy will bleach it to white. White gold is often hard and springy, hard to work but easy to cast. My favorite white gold has no nickel but has Palladium as the chief alloy. It is a very pleasing color, whiter than nickel white gold with a slightly bluish cast. Most articles made of white gold are rhodium plated, because white gold has a slightly yellow hue which makes it look dirty. Rhodium is one of the platinum group of metals as is palladium, both are very white with a slight blue overtone that looks really good in the display cases, but rhodium wears off as you wear the ring. If you want your ring to look best for a long time get it made with Palladium white gold. If you have any questions about gold alloys put them in the comment section on our Walker Goldsmiths web site and I will do my best to answer.