COLORED GEMSTONE EDUCATION
Although gold is not nearly as rare as platinum, it is equally as desirable. Gold does not rust, tarnish or corrode. It takes 17 tons of gold to ore to extract one ounce of pure gold. It then takes three weeks to refine the metal to be used in jewelry.
In its purest form, gold is too soft to withstand the wear and tear of everyday use. So, alloys are added to make gold more durable. Pure gold is 24 Karat, or twenty-four parts gold. It will be stamped 999. 14 Karat gold is 14 parts gold and 10 parts of another alloy (usually silver, zinc or nickel), or 58% pure gold. The stamp will read 14K or 585. 18 Karat gold is 18 parts gold and six parts of another alloy, or 75% pure gold. The stamp will read 18k or 750.
Gold is naturally yellow, but you can find it in white, rose and green. Different colors are achieved by adding different alloys. For example, white gold is made by adding nickel and zinc and rose gold is made by adding copper. Adding silver gives gold a slight greenish tint.
Sterling silver is the third precious metal. It is frequently used in jewelry because it is relatively inexpensive, it is an abundant metal and it is easy to form. Silver is half the weight of platinum and is alloyed with 7.5% copper. Its stamp will read 925.
Tarnish-resistant with a substantial feel in weight. Tungsten is nearly impossible to scratch or wear down, so even the most delicate details are well-defined and polished after years of wear. Four times harder than titanium, tungsten retains its polish longer than almost any other metal. A practical and beautiful choice for gardeners, or anyone who works actively using their hands.
A bright white metal that is highly scratch resistant. Made from a highly durable alloy, cobalt is four times harder than platinum while at the same time, less dense. Because of its natural hardness, cobalt jewelry is extremely scratch, chip and corrosion-resistant. Its lower density and natural malleability allow for strong, dynamic designs with less weight. Cobalt is also hypoallergenic, making it an ideal choice for those with sensitive skin or an active lifestyle.
Platinum is the rarest metal, making it considerably more expensive than even pure gold. Eighty-five tons of platinum are mined annually, compared to the 1,500 tons of gold. Ten tons of ore must be mined to produce just one ounce of platinum. It takes five months to refine platinum before it can be used in jewelry.
Platinum is the purest metal. Platinum is the only precious metal used in fine jewelry that can be 95% pure. Small amounts of iridium and ruthenium (a metal from the platinum family) are commonly added to platinum. The stamp will read PLAT, PT or 950. Platinum’s purity makes it the only truly hypoallergenic metal.
Platinum is also the strongest metal. It weighs 60% more than gold and has a high resistance to heat. It is very dense and extremely resistant to wear. Although platinum will still scratch just like any precious metal, the scratches do not represent material loss.
Relatively soft, very malleable. Pure silver, also called fine silver, is commonly combined with other metals to produce a more durable product. The most popular of these alloys is sterling silver, which consists of 92.5 percent silver and 7.5 percent copper. Although any metal can make up the 7.5 percent non-silver portion of sterling, centuries of experimentation have shown copper to be its best companion, improving the metal’s hardness and durability without affecting its beautiful color.