From the regal yellow of pure gold to the dazzling elegance of platinum, precious metals have long been treasured and coveted throughout history. Each metal possesses many qualities that not only enhance a gemstone setting, but can also reflect the originality and style of the person who chooses to wear it.
Pure Gold is measured in units of fineness known as karats. This is not to be confused with "carats", which is the unit used to measure gemstones. Because pure gold is too soft to be used by itself, it is traditionally combined with an alloy (or base metal) to enhance durability and to influence the color of the gold. Twenty-four karat gold ("24K") is pure gold without any alloys. It has a deep yellow color and a rich luster. Because it is soft and easily bent, it is not recommended for jewelry. Gold of lesser karats (22K-10K) are all alloyed with a combination of silver, copper, nickel and zinc. This adds strength, but if too much is added (in the case of 12K and less) it can dull the color. For beauty and durability, 18K gold is highly recommended.
A karat is 1/24th pure. Pure gold is 24k or .999 fine and very malleable in its purest state. An ounce of pure gold can be drawn into gold wire that would reach 50 miles in length.
USA karat stamping denotes gold purity content:
24K gold is 99.9% or .999
22K gold is 91.6% pure or .916
18K is 75.0% pure or .750
14K is 58.3% pure or .585
12K gold is 50.0% pure or .500
10K gold is 42.6% pure or .426
14K and 18K are usually the karatage of gold you will find in today's marketplace. These gold alloys partially account for the variance in the price you will pay for a specific jewelry item. Both 14K and 18K items are available in yellow and white color variations. Although yellow and white gold are the most familiar of gold colors, gold jewelry may also be found in a variety of other colors including pink/rose, green, and the seldom found blue, purple and black.
Some examples of alloying formulas to achieve gold color variances are: 18K yellow (.750): 75% fine gold, 15% copper, 10% fine silver.
14K yellow (.585): 58.5% fine gold, 29% copper, 12.5% fine silver.
18K white (.750): 75% fine gold, 2 % copper, 17% nickel, 6% zinc.
14K white (.585): 58.5% fine gold, 23% copper, 12.5% nickel, 6% zinc.
18K green (.750): 75% fine gold, 25% fine silver.
18K pink/rose (.750): 75% fine gold, 25% copper.
To achieve the blue or black colors iron is alloyed with fine gold. For purple fine gold is alloyed with specific percentages of aluminum, tin, and thorium.
The choice of a color of gold for your mounting may be a purely aesthetic one, but for those consumers looking for whether a specific color of gold mounting makes a difference in the appearance of their diamond there are some particular aspects of gold color to consider.
Due to the presence of nickel in the white gold alloy, white gold tends to be harder than its' yellow gold counterpart. As a stone setting, this aspect provides more security than a yellow gold setting of equivalent karatage, but the presence of nickel in a white gold setting also increases its' potential for breakage.
If your diamond is colorless or near colorless you may want to set it in a white gold setting even if your mounting is yellow gold. Many traditional engagement rings share this combination. The choice of a white gold setting will insure that your diamond's color will not be influenced by the yellow color of a yellow gold setting.
Depending on the karat gold (14K, 18K or 22K) of your jewelry, the color of yellow gold may vary from a softer shimmering yellow to a bright rich yellow. This is due to the varying alloy combinations. Whatever the subtleties of yellow color you may find it either aesthetically or practically a good choice for setting a yellowish diamond since the yellow setting itself may mask the yellowish color of the diamond.
Highly popular in the early part of the twentieth century, rose gold is enjoying a resurgence of popularity today. The pinkish tone casts a soft warmth that compliments many settings.
Platinum is very rare and expensive, more expensive than gold which may help you to understand why the same stone of choice set in a mounting of platinum is more expensive than the same mounting in karat gold. Rare, valuable, and durable, platinum is the purest of all metals used for fine jewelry. The beautiful cool white luster shows little wear, making it an ideal setting for gemstones. In the United States a jewelry article stamped platinum must be at least 90% platinum.
This grayish white to silver gray metal is harder than gold and very durable with a hardness of 4-4.5 on the Mohs hardness scale, equivalent to the hardness of iron.
There are various platinum alloy combinations available in jewelry as reflected in the quality stamps a platinum jewelry item may bear (10 % IRID PT = 10 % iridium, 90 % platinum, or PT950 = 95% platinum).
Jewelers working in platinum require some special skills as well as some special equipment for the repair and manufacturing of platinum jewelry. This expertise and additional equipment adds to the cost of a platinum jewelry repair or the choice of a platinum mounting.
This ultra lightweight, refractory gray colored metal is extremely durable. Primarily used by the aerospace industry, it has recently been appropriated by the jewelry industry for its unique coloration and non-corrosive properties.
Pure silver is .999 fine and has a soft lustrous whitish color that can be polished to a bright mirror like finish. Today's silver jewelry is primarily a silver alloy, 92.5% fine silver and 7.5% copper, commonly known as Sterling silver and is quality stamped .925, SS or Sterl. Another silver alloy you may encounter is known as coin silver, usually 90% fine silver and 10% copper, quality stamped .900.
Silver deposits can be found in various parts of the world with Mexico being the leading silver producer followed by the USA, Peru, Canada, and Australia. Silver is the most common metal used in jewelry today.