How Do I Know What I am Really Buying? Part 4

Last time I promised to talk about Plating and Filled Metal

Plating with precious metal has been around for a very long time. Theophilus, in his book “On Divers Arts”, published in 1122, describes how to gild a surface, First you mill together mercury and gold, and then apply it to a metal surface and drive off the mercury to create a gilded surface. He notes “Be very careful that you do not mill or apply gilding when you are hungry, because the fumes of mercury are very dangerous to an empty stomach and give rise to various sicknesses…” And I should mention that the milling process is expected to take three or four hours. Fortunately today there are considerably less toxic plating techniques available, involving electricity and chemical solutions. Until fairly recently almost all precious metal plating solutions contained cyanide, but now non-cyanide plating solutions are available for the shop jeweler. Base metals can be plated with silver or gold, both with the same intention, to make a less expensive metal appear to be a more valuable. Plated pieces should be labeled as plated, and some may be stamped with the purity of precious metal that was used. The layer of precious metal is just a few molecules thick, and there is no standard to indicate how thick the precious metal is. Religious objects were often gilt during Medieval times to make them look as if they were made of solid gold.

Zemanta Related Posts ThumbnailAn exception to the plating rule is Vermeil, which is Sterling silver that is plated with gold. It is an American standard. By law Vermeil has no less than 2.5 microns of karat gold (no less than 10k purity) layered over the Sterling Silver. It is usually stamped Vermeil and may include a purity stamp for the gold. Vermeil is 50 times heavier than standard gold plating.

Beware of “Dutch Gold”. It is not real gold, but rather an alloy of copper and zinc, and is usually sold in leaf form. It is sometimes used to “gild” jewelry and other objects. It can be very beautiful, but it is NOT gold.

Filled Metal is made using a different technique than plating. Filled metal has a physically bonded layer of precious metal that is much thicker than plating. It is attached through a combination of heat and pressure to a base metal core.  When purchasing metal stock from a supplier the metal will be listed according to the purity of the gold or silver. For instance 14/20 or 12/20 for gold means 14K or 12K. The ” /20″ part refers to the ratio of karat gold to core by weight, which is 5%. That means the precious metal is 5% of the overall weight of the metal. Different suppliers use different purities of gold.

English: Diagram of gold filled jewellery

English: Diagram of gold filled jewellery (Photo credit: Wikipedia)

Silver filled has a different annotation system. My supplier lists it as either 1/10 or 1/20, which means a ratio by weight of 5% and 10% respectively; 5% or 10% of the total weight of the metal is silver. I do not use silver filled materials in my shop. I feel that the difference in price is not worth it. But gold-filled materials can allow the customer to have the look of real gold in a product for a fraction of the cost of solid gold.

Next Time: Consequences

Choosing Which Metal To Use – Part 4

Last time we asked: What about silver plate, silver filled, vermeil, and gold filled metals and sources of metal?

I only use solid silver in my shop for cast pieces, plate and wire. The differences in cost between silver plate, silver filled, and solid sterling silver metal is, in my opinion, not sufficient to warrant using the less expensive metal. If I am using wire to make a knit chain necklace, the cost of the metal is important, but the majority of the cost is actually in the labor. Some of my less expensive bracelets and necklaces may have silver plated clasps.

Vermeil is sterling that is gold plated. This term is rarely used outside of the United States. I use vermeil, gold filled, and gold plated clasps for necklaces and bracelets. Vermeil is the same thing as silver gilt or gilt silver which was a very common period technique. Medieval people often could not afford solid gold items either. Gilt bronze was often used, especially for large items, like bowls and reliquaries.

English: Reliquary from Limoges, France, c. 12...

English: Reliquary from Limoges, France, c. 1280-1290, champlevé on gilded copper, Honolulu Academy of Arts (Photo credit: Wikipedia)










With the price of gold over a thousand dollars an ounce, solid gold is too expensive for your average customer. Gold Filled wire allows me to create affordable “gold” knit chain necklaces. Filled metal has a physically bonded layer of precious metal that is much thicker than plating.

English: Diagram of gold filled jewellery

English: Diagram of gold filled jewellery (Photo credit: Wikipedia)













And what about sources of metal? Any reputable metal distributor in the USA will be able to give you the actual metal content of an alloy. This is important for a number of reasons. The lead laws are one, but knowing the metal content of my supplies can be very important to my customers. Metal allergies are not that uncommon. By keeping an alloy list in my shop I can easily answer people’s questions about whether they can wear something or not. Most people will turn green from any copper alloy, I know that I certainly do, but some folks get serious contact dermatitis from nickel and other metals.

The vast majority (about 95%) of my metals come from a green US company that guarantees the metal content of their alloys. This is a serious benefit to me when I am developing new products. Each metal has very specific attributes. How much can it stretch or bend before it cracks? If I draw the wire down, will it become a lot harder and springier, or just a little.

I know people who enjoy making their own alloys, and the best of them have considerable knowledge in metallurgy. Knowing what is in the metals that you are alloying is critical. Using random bits of metal can create unanticipated issues, including lead content. I often wonder, when I see the prices of some of the items coming out of the former Soviet bloc countries, just what the metal content is. When a cast piece is selling for less than my cost to produce it, it makes me wonder. I think I will stay with guaranteed alloys from US companies!