Jewelry Information: Metal Plating, Metal Types & Weights
See also our Jewelry Tips and Tricks page, or go back to our Jewelry Glossary index)
Metal Plating and Filling:
What you see is not necessarily what you get--less expensive metals can be superficially transformed by the application of another type of metal onto the original's surface.Gold Electroform: This is not plating, but is a method by which the mold of the jewelry piece is electrically coated with layers of gold. The mold is then removed, leaving only the gold. Electroformed jewelry has a "big look" because it is hollow--the process is suitable mainly for pins, brooches and pendants which are not subject to rough handling, since the gold is very thin (about .003-.007 in.) and can be easily dented.
Gold Filled (GF): A process by which a relatively thick layer of gold is mechanically applied to a base metal and fused by heat and pressure. The layer must be at least 10K gold and 5% of the total weight of the item. Gold Overlay and Rolled Gold Plate is the same as GF, except only 2.5% of the item must be gold.
Gold Electroplated (GEP): A layer of gold at least 7mils (7/1,000,000 of an inch) thick is electrically deposited onto the base metal by immersion in a liquid containing chemically bound gold molecules. Gold Flashed or Gold Washed is the same as GEP, except the gold is less than 7mils thick. Except for our 24K Rose, ViridianGold.com does not sell GEP items--however, some jewelry items may have plated accents in contrasting gold color.
Ion Plating: A process by which atomic-sized ion particles of metal are deposited via an electric beam onto another metal. Depending on the type of metal used for the ions, different colors may be plated.
Palladium Plated: Jewelry items may be plated with Palladium, rather than Rhodium (below), to enhance whiteness, since Palladium is also a naturally white, platinum-group metal, and much less expensive than rhodium.
Rhodium Plated: Rhodium is a member of the Platinum family of metals--it is actually whiter and harder than platinum. Rhodium is used to plate most white gold in order to give it a more durable finish and a whiter color and sometimes is used to plate sterling silver to resist tarnishing (when sterling silver is plated with rhodium, it should not be polished for this will eventually remove the rhodium's protective effect). Some yellow gold jewelry items may have rhodium-plated accents. Rhodium is very expensive, about five times the cost of platinum.
Vermeil: Pronounced "vair-may", it is sterling silver which has been plated or rolled with genuine gold. If a gold-colored item is marked "925" or "STER", that usually indicates that it is vermeil.
Metal Type / Weight:
Gold is the most popular metal for fine jewelry today, with platinum gaining in popularity. Other metals such as sterling silver, stainless steel and titanium are also used in fine jewelry. At ViridianGold.com, the weight of a jewelry piece refers to its gold content. Therefore, a 14K diamond ring specified as having a weight of 4.4 grams indicates that the ring is composed of 4.4 grams of 14K gold, exclusive of the weight of the stones. For rings that we offer in different stock sizes, the weight given in the product description is for the standard stock size of 6 for women's rings and 10 for men's rings. When comparing gold or platinum jewelry, always note the weight of the piece rather than its size dimensions, since two pieces that are similar in appearance may have significantly different gold content, and hence value. See our helper page for weight and size comparisons of U.S. Coins.Gold: Gold is too soft in its pure state to be used for most kinds of jewelry. Pure gold is specified as 24K, where "K" is the abbreviation for karat, a measure of purity (not to be confused with carat, a measure of weight). In order for gold to be usable for jewelry, it must be mixed with other metals to form an alloy which is stronger than gold in its pure form. So, 14K gold is 14/24 pure, or about 58.5% gold and 41.5% other metals--copper is used in both yellow and white gold, with silver being added for yellow gold and nickel for white gold. 14K gold is thus stronger than 18K gold, and yet retains the bright color indicative of gold, even though it is less costly and contains less pure gold than 18K does. White gold is usually also plated with rhodium, which is a platinum-group metal, in order to enhance its whiteness. Often, yellow gold is selectively plated with rhodium to form a two-tone color scheme, such as a yellow gold setting with the setting prongs of the diamond plated with rhodium. Gold is also specified by fineness, where a fineness of 1000 indicates 100% purity. 14K gold thus has a fineness of 585, and this number is often stamped on jewelry instead of the karat mark; 10K gold has a fineness of 417 (41.7% gold). In order to be called "gold" in the US, the metal must be at least 10K. To learn more about gold, its standards and mining, go to the World Gold Council website.
Palladium: This white, platinum-group metal is quickly growing in popularity now that new alloys allow for quality casting while maintaining 95% purity, and many are predicting that it will replace white gold as the white metal choice for jewelry. Palladium is similar in hardness to 14K white gold, and is thus harder than platinum. In addition, it is 44% less dense than platinum, and costs much less per ounce--thus, jewelry made with palladium is much less costly. Like platinum, it does not require alloying for whiteness, and thus it is naturally hypoallergenic (contains no nickel). Palladium is about 1/3 the cost (per gram) of platinum. For more information about palladium, its characteristics and how it is mined, go to the StillWater Palladium website.
Platinum: Prior to the 1940's, platinum was popular in engagement and wedding rings, but it was outlawed for non-military use at the outbreak of World War II. White gold was substituted, and remained popular even after the war because of its lower cost and easier fabrication--however, in the last 15 years platinum has increased in popularity. Pure platinum, unlike pure gold, is structurally strong, partly because it has a higher density and melting point, a characteristic which makes it more difficult for jewelers to work with--however, platinum is softer than 14K white gold and therefore scratches more easily. Because of its natural properties, platinum jewelry need not be as highly alloyed as gold--platinum jewelry with a fineness of at least 950 (95% Platinum) may be marked simply as "Plat." or "Pt.", but if the fineness is less, the piece must be marked to indicate this, such as "900 Plat. (90% Platinum)." Note that all platinum jewelry sold by ViridianGold.com is 950 fineness and will be marked thusly. The alloy most commonly used for the other 5% in our jewelry is Ruthenium. Since platinum is true white, it does not require rhodium plating as white gold does, and is naturally hypoallergenic (it does not contain nickel). For more information about platinum, consult the International Platinum Association website.
Sterling Silver: Silver is the whitest of all jewelry metals. Like gold, silver is too soft to use for jewelry in its pure state, so it is usually found as Sterling Silver, an alloy of 92.5% silver and 7.5% other metals, usually copper. Items marked with "SS" or "925" are sterling silver. Sterling silver will tarnish, of course, but when manufactured as highly polished, sterling silver will need little if any polishing when worn as jewelry. Sometimes silver is plated with rhodium to prevent tarnishing (and if so, it should not be polished for this will remove the rhodium's protective effect), or with gold to produce a type of metal called vermeil. We will always tell you in the specifications if a silver jewelry item is rhodium plated. For more information about silver, go to the Silver Institute website.
Black Silver: A black, naturally-occurring silver ore which is 68.8% silver, combined with antimony and sulfur.
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Authored by: Bill Long
