Nearly all metals are alloyed--or mixed--with others to strengthen them, make them more colorful, or even reduce the price. The only metal that isn't alloyed is 24K gold, which is 99% (or more) pure gold. That less than 1% allows for other naturally occurring materials found in pure gold ore.
Most of the yellow-toned gold jewelry in my collection is actually green gold. I love green gold because it's got a cool undertone and an old-world richness to it. That's because it's alloyed with a larger proportion of fine silver and a smaller amount of copper (specifically, 80% fine silver and 20% copper) than yellow gold, which has a higher ratio of copper in the alloy (specifically 40% fine silver and 60% copper). And rose or pink gold has even more copper in the alloy that lends a rich, warm tone to the metal.
Unless I point it out, most people don't see much color difference between yellow and green gold in person but when they do see the difference, it's always exciting. And my clients who historically don't wear gold because they don't think it compliments their skin tone are happily surprised by how flattering green gold is on nearly every skin tone. Green gold also provides a much richer contrast when combining metals and it makes a gorgeous trio with platinum (or sterling silver) and rose gold.
All of the pieces in my collection feature my trademarked Cashmere Finish®. I love the softness and richness of cashmere and I want to imbue that feeling in my jewelry. You'll notice a soft subtle glow in my pieces that beautifully compliments my organic shapes.
There are various hallmarks for metals but regardless of the alloy (other metals including silver, copper, zinc, nickel [which is not used in my jewelry]) and color of the gold, the ratio of pure metal to alloy must, by law, remain consistent. Here are the hallmarks to help you identify your precious metals.
GOLD 24K Hallmarks used are: 24K, 999, 990 (99.9 or 99% pure gold)
22K Hallmarks used are: 22K, 916 (91.6% pure gold plus 8.4% alloy)
18K Hallmarks used are: 18K, 750 (75% pure gold plus 25% alloy)
14K Hallmarks used are: 14k, 585 (58.5% pure gold plus 41.5% alloy)
PLATINUM Hallmarks used are: PLAT, PT, 950 (95% pure platinum plus 5% alloy)
SILVER Fine silver Hallmarks used are: 999 or 999FS
Sterling silver Hallmarks used are: 925 (92.5% fine silver plus 7.5% alloy) or STERLING SILVER. (This applies to U.S. hallmarking standards.)
Sterling silver hallmarks can vary in other parts of the world, so look closely at your jewelry and always ask the jewelry maker what metal you're purchasing. And be sure to ask for it to be clearly labeled on your sales receipt.