Say you have two diamond solitaire rings, one set in platinum, and one set in gold. Both are worn the same way by the owners, but which will stand the test of time? Platinum is ultimately the most durable of all the fine metals. If you were to knock a platinum prong, the prong would move slightly and maybe "squish" a little (as much as metel can really "squish"). If you were to knock a gold prong, a small bit of the prong would shave away. Over time, the platinum will have more metal left over, where as the gold will wear down faster.
Because platinum is, as I call, a "squishy" metal, this also means it is much more likely to scratch than gold. Now, let me make this clear, I'm mostly talking about 14 karat gold. I'll get more into the differences in the karats of gold in the next section. Gold is likely to hold a high polish much longer than platinum.
Platinum is a nearly pure metal when used in jewelry. Most often you will see "950" stamped in a piece of jewelry. This means that there is 95% platinum, and 5% alloy. The alloys typically include ruthenium , copper, cobalt, iridium, rhodium, or palladium. Occasionally you will see "900" stamped, which means 90% platinum and 10% alloys. Because platinum used in jewelry is typically 95% pure, this is a great choice for people who have allergies. Platinum is also a naturally grey-white metal, so there is no need to have the ring plated.
Gold used in jewelry is usually 10 karat, 14 karat, or 18 karat. Pure gold is 24 karat, which means it's 99.99% gold. Gold is naturally a very soft metal, so it's not ideal for jewelry that takes a beating, such as engagement rings or bracelets. Occasionally you will see 24 karat or 22 karat as bright yellow accents on a piece of jewelry. Alloying gold with other metals makes the gold harder.
Sometimes a piece will be marked 10K or 18K, but sometimes you will see numbers instead, such as 585 or 750. These indicators tell you how much pure gold is in the piece. Here is the breakdown of gold karats
: 8K or 333 contains 33.3% gold; 9K or 375 contains 37.5% gold; 10K or 416 contains 41.6% gold; 12K or 500 contains 50% gold; 14K or 585 contains 58.5% gold; 18K or 750 contains 75% gold; 22K or 916 contains 91.6%; 24K or 999 or 1000 is 99.9% or 100% pure gold. The mark .999 or .999 fine also means pure gold.
Some people are purists and prefer 18 karat jewelry, because there is a higher gold content, but is durable enough for daily wear (unlike softer gold like 22K or 24K). But most people are okay with 14 karat because it is actually a harder metal and it lowers the cost of the piece a bit. A personal suggestion, I typically encourage my customers to choose 14 karat for white gold because white gold has to be rhodium plated anyway, so they will look the same, and 18 karat for yellow gold because it has a nicer yellow color to it.
Since gold is not naturally white, when we allow yellow gold with other white metals to make it "white", there is still a slightly yellow-ish color, so that's why we
white gold. Depending on how rough you are on your jewelry, depends on how often you should have it done. On average I'd say people get their jewelry re-plated between six months and two years.
Some of you may have heard that platinum and gold are almost the same price per ounce, so why is platinum more expensive? Platinum is a more dense metal, meaning a ring made of platinum will weigh more than the exact same design made of gold. In addition to that, platinum is a nearly pure alloy, unlike most gold jewelry. So a platinum band that weighs 0.34oz contains 95% platinum, where as the same band made of 14 karat white gold weighs 0.21oz contains only 50% gold.
Some may shy away from platinum because of the cost or simply because they feel the piece i too heavy for their comfort. Palladium
is a nice alternative to platinum or white gold. Palladium will cost around the same price as gold, but is a nearly pure metal allow like platinum, and not quite so heavy.