Precious Metals

Gold, silver, platinum. These tempting elements have brought more than their share of joy and woe to people over millennia. The final session of my gemstones class covered the precious metals in which those beautiful stones are set. The fictional criminal I have in mind picked up a few good tips in this session too.

Gold’s purity is measured in karats, with 24K gold 100 percent pure. 18K gold is 75 percent gold and 25 percent alloy, and so on. Pure gold is much too soft to be made into jewelry. In the United States, 14K (58.3 percent gold) is common in fine jewelry. In other countries—notably, India and the Near East—18K gold is more typical.

Not only are gold alloys more durable for jewelry, having less gold makes them less expensive than pure gold would be and allows for a change in the color. Our instructor emphasized that gold is yellow. White gold, rose gold, and green gold are all possible because of the alloys used. Pink gold is produced through the addition of copper; green gold by adding silver; and white gold includes palladium (expensive) or nickel (cheap), for example. An opportunity for a scam there, it seems.

Gold is also hypoallergenic, so if someone has an allergic reaction to their gold jewelry, they are actually sensitive to whatever metal the gold was alloyed with. Many people (including me!) get an itchy rash when there’s nickel in their jewelry (the backs of inexpensive earrings, for example), so sticking to yellow gold is best for them. Of course, such a dermatologic reaction might raise a buyer’s suspicions. Interestingly, and of potential benefit to our fictional jewelry scammer, the Federal Trade Commission does not regulate the alloys used in jewelry manufacture, just the percentage of gold present.

While nickel is inexpensive, palladium is very expensive, so to achieve the desirable level of whiteness in white gold, it may be plated with some other metal—typically rhodium. White gold today is so expensive, “you might as well buy platinum,” our instructor said. My thief is pondering that in planning his next smash-and-grab.

Prices of the precious metals are high, because of high demand, and can rise quickly when people are nervous about other investments or in the midst of various national or international crises. And some of the countries gold is mined in are not the most stable or as subject to environmental or purity standards as is the United States or European Union. (Foreign intrigue afoot.)

Like gold, most silver is an alloy. Sterling silver is 92.5 percent silver and the remainder copper, which provides strength. It’s not as hard or as tough as gold.

Previous posts in this series:
Diamonds and Pearls
Colored Gemstones

Photo: PhotoMIX-Company for Pixabay