Gold

Gold and costume or fashion jewelry

While solid gold used in fine jewelry is much too expensive to use in costume or fashion jewelry, gold is still used by plating it onto a less expensive metal.

Gold Filled

Heat and pressure is used to apply a layer of karat gold to a base of less costly metal, often copper, brass, or steel. The jewelry appears gold but since only a fraction of the metal is actually gold it is much less expensive. To be designated as gold filled at least 1/20th of the total weight of the metal must be karat gold. The stamping of a piece of jewelry that is 14k gold filled will read something like “1/20 14k G.F.” or “14k G.F.”

Rolled Gold Plate

The same process that is used for gold filled metal is also used for rolled gold plate but the layer of gold will be thinner, it is not required to be 1/20 karat gold. The stamping for this type of plating is “1/30 or 1/40 14k R.G.P.” or “14k R.G.P.”

Gold Electroplate

Electroplating, used for gold and silver, is the process of applying a layer of precious metal to a less expensive metal through the process of electrolysis. The base metal is immersed in a tank of water and chemicals with a piece of gold. An electric current is run through both metals which carries gold ions across to the base metal, bonding to the surface of the base metal. This is the cheapest plating method and usually, though not always, produces thinner layer of gold than gold filled or rolled gold plate. Plated jewelry is often not stamped at all but may be stamped “gold electroplate”, “G.E.” or “H.G.E.” (heavy gold electroplate).

Vermeil

Using the same process as electroplating, a layer of gold is applied to silver instead of a base metal. Since silver is also a precious metal, vermeil jewelry is usually considered fine jewelry, unlike jewelry that is gold plated over a base metal.

Regardless of the method used, gold plated jewelry has its drawbacks. Since the gold layer is very thin it will wear away over time to reveal the metal beneath, however the thicker the layer of gold the longer the beauty will last. Plated jewelry should not be polished, since the process of polishing removes scratches by removing a layer of metal. Polishing will most likely remove the thin layer of gold revealing the metal beneath.

Silver

In addition to being the least expensive and most plentiful of the precious metals, silver is considered to be the “whitest” of the white metals, including the platinum family of metals. Silver is a beautiful metal that takes a high polish and has a nice feel. A softer metal, silver is less durable than karat gold or platinum but its main drawback is the fact that it tarnishes easily. Though modern chemical cleaners can easily remove tarnish, some vintage pieces of silver jewelry are actually enhanced by a layer of tarnish giving them an aged patina.

Like gold, silver is available in various levels of purity.

Type	Purity	Fineness Mark	Uses
Fine Silver	99.99% or .9999	999	Bullion investment products, it is generally considered too soft for industrial, commercial, or jewelry use.
Britannia Silver	95.84% or .9584	958 (since 1999) was formerly the symbol of Britannia	Introduced in England in 1697 to replace sterling silver for items of “wrought plate” in an attempt to limit the clipping and melting of sterling silver coinage. After complaints from the trade because Britannia silver is softer than sterling silver, sterling was again authorized for use by silversmiths in 1720.
Sterling Silver	92.5% or .925 or higher	925 or higher	Jewelry
Coin Silver	90% or .9000	900	US Silver coins

The European market handles alloys with 87.5%, 83%, and 80% silver and should be marked with its actual fineness.

Silver and costume or fashion jewelry

Silver Filled

Silverplate

Vermeil

Platinum

The Platinum Group

Platinum is the rarest and most expensive of the precious metals, not to mention the most durable. Platinum has been used in jewelry only relatively recently. This is because platinum has a melting point of 3190°F or 1755°C, much higher than gold or silver. The old-fashioned jeweler’s blowpipes were not adequate for working it unless they first combined it with arsenic, which was obviously dangerous. As a result, it wasn’t until the invention of the oxyhydrogen torch in the mid-1800s that made working with platinum practical.

Platinum occurs in association with other rare metallic elements known collectively as the platinum group metals. They include platinum, iridium, palladium, ruthenium, rhodium, and osmium. Platinum is the most abundant, but all, with the exception of osmium, are used in jewelry.

Jewelry platinum is typically an alloy of 90% platinum and 10% iridium as a hardener. An alloy of 95% platinum with 5% ruthenium hardener is as hard, while 95% platinum with 5% iridium is softer. Palladium alloyed with a small amount of ruthenium has been used largely in setting heads, with the advantage of being lighter and less expensive, but it does not hold the stones as firmly.

Rhodium is primarily as a plating metal to give white gold and platinum a bright, hard finish, and to slow tarnishing on sterling silver. It is also common practice to rhodium plate yellow gold heads in which diamonds are set.

The hardness of platinum allows for finer, more delicate, filigree than can be achieved with gold or silver.

Fineness Marks

Platinum jewelry is usually marked Platinum, Plat, or PT followed or preceded by numbers indicating the percentage of platinum.

Silver, White Gold, or Platinum

Silver is the least expensive and the whitest metal but tarnishes easily and is more difficult to work with the torch. White gold resists tarnishing better and for torchwork is easier to control but is more expensive, tends to yellow, and is harder to shape. Platinum is harder and responds well to mechanical tooling, holds stones securely, and resists tarnish well but it is the most expensive and heaviest metal, requires high torch temperatures, and is more difficult and expensive to work.