Articles by EJA Members
Metals Defined
by Ahna of Art Created
Gold
Because pure gold is to soft to resist prolonged handling, it is usually alloyed with other metals to increase its hardness for use in jewelry, goldware, or coinage. Most gold used in jewelry is alloyed with silver, copper, and a little zinc to produce various shades of yellow gold or with nickel, copper, and zinc to produce white gold. The color of these gold alloys goes from yellow to white as the proportion of silver in them increases; more than 70 percent silver results in alloys that are white. Alloys of gold with silver or copper are used to make gold coins and goldware, and alloys with platinum or palladium are also used in jewelry. The content of gold alloys is expressed in 24ths, called karats; a 12-karat gold alloy is 50 percent gold, and 24-karat gold is pure. Rose gold or red gold is alloyed with copper to give its hue.
24 Karat - 100 percent pure gold.
22 Karat - 91.7 percent pure gold.
18 Karat - 75 percent pure gold.
14 Karat - 58 percent pure gold.
10 Karat - 41.6 percent pure gold.
Gold Plating
A metal item that has a very thin layer of gold applied to it by a process known as electro-plating. Tends to wear away more quickly than a gold filled item.
Gold Filled
Also known as gold overlay. These terms refer to a gold layer that has been bonded to a support metal. To qualify, the gold must be at least 10% of the total weight. Gold-filled jewelry is similar to gold-plated; they have an exterior of gold and a core of base metal, usually copper. The difference is the process of application.
925 Sterling Silver - Contains 92.5% pure silver
999 Fine Silver - Contains 99.9 % pure silver
Silver Plated
A metal item that has a very thin layer of silver applied to it by a process known as electro-plating. Tends to wear away more quickly than a 925 or 999 item.
Vermeil
Gold plated silver. Deriving from the French word for "veneer", it is also referred to as onlay or double.
Platinum
Sixty times rarer than gold, platinum is only found in a few locations worldwide - Russia's Ural Mountains, South Africa's Merensky Reef, and a few small mines in the U.S. and Canada. Relatively new to the jewelry market, platinum is fast becoming incredibly popular and is already a bedrock of the contemporary jewelry landscape. Purer, stronger and denser than gold, platinum is considered by many to be the ultimate and most luxurious of all the precious metals.
Metal Terms
by Julia of Ivorys Arts
I'm going to describe and illustrate a couple of terms that you may come across when looking at pieces of silver jewelry, especially vintage or antique pieces.
Bali or Balinese - After reading a question from someone asking what Bali silver was, I decided that this should be included. Bali is an island in Indonesia noted for their sterling work. It is a very popular source of beads, toggle clasps, chandeliers and other jewelry-making supplies because of the ornate and detailed handiwork on their beads. The large focal bead shown below is an example.
Niello - This term refers to a silverworking finish, where the design is done in polished silver and enhanced by a matt black background. This often shows up in pieces that are stamped Siam, which formally became Thailand in May of 1949. Thus, any pieces you come across that are stamped Siam probably date back at least 50+ years. The leaf brooch with the dancer shown below is typical of Siam pieces.
Repousse' - This refers to a style of silverwork, where raised areas are created by hammering the piece from the back, then detailing it from the front. Danecraft made exceptional use of this style of silverwork in many of their sterling pieces. The silver lily brooch shown below is a classical Danecraft piece. |