It’s the oldest, precious metal known to mankind. Throughout history, gold has been the foundation of many monetary systems and remains important to our economy today. Gold is also a popular metal of jewelry designers because of its versatility. It is used for objects of art, religious items and, of course, jewelry. Because it is such a soft metal, it can be molded, shaped and carved into very intricate designs. Its warm color is very appealing, it’s hypoallergenic and it doesn't rust, tarnish or corrode. The major source of the world's gold is South Africa.
Unlike other precious metals, pure gold is so soft that it is rarely used in jewelry, but rather is mixed with another metal (this is called “alloy”) - usually copper or silver - to make a stronger gold alloy, or mixture of metals. The amount of pure gold in an alloy is expressed in karats (versus the carat weight used for measuring diamonds and other gems).
An interesting caveat….. ”CARAT” vs “KARAT” -
“Carat” spelled with a “c” came about in ancient times, when diamonds were weighed on a balance scale against a carob seed. When the diamond weight equaled the weight of one carob seed, it was said to be one “carob”. With time, the term “carob” evolved into the term “Carat”. Hence, “Carat” or “ct” is used ONLY in weight measurement of gemstones (i.e. 1.0ct).
The term “Karat” or “kt” applied ONLY to precious metals (i.e. 14kt).
The higher the percentage of pure gold, the higher the karat. Pure gold is 24K, while 10K gold - the minimum that may legally be called karat gold in the United States - is 10 parts gold to 14 parts other metal. The standard is 14K in the United States, 18K in Europe and 22K in India, Japan and some other Asian countries.
This is the actual content of pure gold in each of the KARATS:
18K is 75% pure gold
14K is 58% pure gold
10K is 42% pure gold
Ten karat gold is the lowest level allowed to be manufactured in the United States.
Jewelry made of higher-karat gold is more yellow in color and slightly softer than gold jewelry made of lower-karat gold, which may include copper, silver, zinc, or other metals.
**You, the consumer, need to be concerned with the alloys if you are allergic to certain metals or have a high acid content in your body. Acid can turn the jewelry that you wear on your body to black and appear to be of poor quality when it actually is not
Pure gold (which is always yellow) is too soft for jewelry use. The metals that are mixed with pure gold for strength can also modify the color of gold resulting in different shades of yellow, white, and pink gold. White gold was originally developed to imitate platinum, and is usually an alloy containing 25% nickel and zinc. If stamped 18 karat, it would be 75% pure gold
To regulate the use of gold, the United States passed the National Gold and Silver Stamping Act, which states that if an item is marked with its quality, (14K, 18K, etc), that mark should be accurate and within the tolerances provided by the Act.
"Solid gold" refers to an item that contains some gold (at least 10K) and is not hollow.
"Gold-filled" is a process by which a layer of gold (at least 10K) is mechanically bonded to a base metal.
"Gold-plated" means that an item has a plating (or coating) of gold alloy of at least 10K, though usually less gold than in gold-filled items
“Vermeil” (pronounced "vermay,") is a French word describing sterling silver that has been electroplated with at least 100 millionths of an inch of karat gold.
As the karat weight drops, the metal becomes more durable but less yellow. Sometimes gold that is a lower karat weight will be plated in high-karat gold to enhance the color. This is perfectly acceptable as long as you pay a fair price. Keep in mind that gold plating will wear off with time, and the jewelry may need to be re-plated.
The surface of gold jewelry is treated in many ways to enhance the design. Styles like satin, brushed or matte that create soft, lustrous looks to a hammered finish that produces a bright, irregular surface texture offer consumers a variety of looks.
White gold was developed circa 1920 to be used as a substitute for platinum. White gold has the same properties as yellow gold, but it has been mixed with different metals to give it a white color. Instead of the copper and silver used in yellow gold, white gold contains metals like nickel, zinc, or even platinum. These metals, in essence, tend to bleach its yellow color towards white. Nickel and palladium and platinum are strong bleachers of gold; where silver and zinc are more moderate bleachers. However, white gold should not be confused with platinum, which is much rarer than gold and hence much more valuable.
There are 2 basic classes of white gold - the Nickel whites and the Palladium whites. The nickel-whites tend to have a colder white color, whereas the palladium whites have a warmer color. Good nickel whites tend to be hard and difficult to process. Good palladium whites tend to be soft, but are much more expensive, because of the price of palladium. Consequently, many commercial white alloys are done in nickel or palladium and contain some copper; hence, color is compromised.
White gold jewelry is often plated with rhodium. There is, as yet, no legal or industry-accepted definition of what constitutes a 'white' color in gold's and hence the trade description of 'white gold' may not mean an alloy that is 'ice white' or 'detergent white'. For good technical and economic reasons, many commercial white gold are not a good white color (usually a yellow-brownish tint) and are often rhodium-plated to improve appearance.
Rhodium is one of the platinum family of metals and has a high reflectivity and good metallic white color and is hard with good wear properties. A thin electroplated coating is often applied to white gold jewelry to improve its white appearance.
This is legally allowed in many countries, including those with Hallmarking regulations. Such a coating, if not subjected to undue abrasion, should have a lifetime of, typically, 3 years before it wears through to reveal the gold alloy underneath.
For many consumers, the color of rhodium has become the norm for the color of white gold, because that is what they are used to seeing on Jewelry described as white gold!
The same karat weight system is used for both white gold and yellow gold. The white color is an excellent setting for very white diamonds, and when used side by side with yellow gold, it creates a striking effect. Jewelry using both white and yellow gold is called "two-tone."
KARAT MEASURE GOLD VS. ALLOY CONTENT
The nickel skin allergy problem
** Unfortunately, many people (around 12-15%), the female population especially, are allergic to nickel in contact with the skin and this gives rise to a red skin rash or irritation. This problem applies to costume/fashion Jewelry, white gold and steel Jewelry, zippers and fasteners and other body piercings. Much Jewelry is now advertised as 'non-allergenic' or 'nickel-free'.
Buying white gold Jewelry
As stated above, some white gold Jewelry sold may contain some nickel and still conform. Sensitized people may find that they react to such jewelry. Rhodium-plating should provide some limited protection, but remember electroplatings are often porous and will, in time, wear away!
White gold Jewelry wearers can be disappointed to discover that their Jewelry has gone off-white, even a yellow-brown tint, as the rhodium plating wears through (some cheaper Jewelry may well be distinctly yellow-brown in color).
There is currently no legal requirement in many countries for the retailer to tell purchasers if the Jewelry is rhodium-plated. This applies to some platinum Jewelry as well as white gold. If the Jewelry is rhodium-plated, then you cannot know how white (or not) is the gold alloy underneath. A good quality white gold, with good color, should not need to be rhodium-plated but may well be to conform to a consumer expectation. If the rhodium plating does wear through, the Jewelry can be easily re-plated and the good color restored.
BLACK HILLS GOLD
Black Hills Gold is an unusual style of gold jewelry manufactured in the Black Hills of South Dakota. It is produced from 10 karat yellow gold with 12 karat rose gold and green gold accents. Most Black Hills Gold jewelry is styled with a grape and grape-leaf motif.
How to Buy Gold
When buying gold always look for the karat mark to ensure that it is real. Pure gold is usually 24K and is much too soft to make jewelry so it is alloyed with other metals to increase its strength. Remember….. jewelry marked 18K gold means it is 75 percent pure gold. The designation placed on gold like the karat and the maker’s trademark is to ensure that it is real gold. In the United States the most common karat of gold is 14K. Nothing less than 10K gold can be legally sold in the United States. However, lower karatages are popular in other countries.
Care for Gold
Always keep gold clean and never use harsh chemicals to clean it with. Gold can easily be scratched so keep it is a fabric lined case and away from other jewelry. If a piece of a setting breaks you can always take it to your jewelry professional and have it repaired. The following chart shows the proportion of pure gold in the most common karat counts:Y ONTENT