SPOTLIGHT ON ... ARTICLE
October 2006

Jewelry Metallurgy Explained
Written by: Lisa Kan

I'm sure as you navigate through the aisles at shows or browse in bead stores, you've wondered a bit on what metals are the best to use for your jewelry making. Sure some of the beads or findings look the same, like silver plated and sterling silver or gold plated and gold filled. But are they really the same to your customer? Are you confused with the differences between gold-filled, gold plated and vermeil? Do you know the durability of each and the science behind the metals? Are you concerned about allergic reactions of your customers? You're spending a lot of time procuring the beads and designing the piece, so why would you skimp on what holds everything together, the findings!

I hope to provide you with a quick synopsis of the most popular metals used in jewelry with this article. And although price may be the most important factor on what you decide to use, it is always best to keep in mind your customer's needs and wants. Your reputation depends on your selection.

Common Metals in Jewelry

Gold Category

Yellow gold is made by mixing pure gold with alloy metals such as copper and zinc. Below is a breakdown of the percentage of pure gold in each of the popular karat weights. It is not legal in the United States to sell any gold lower than 10kt.

24kt gold is pure .999 gold
22kt gold is 91.7 % gold
18kt gold is 75% gold
14kt gold is 58.3% gold
12kt gold is 50% gold
10kt gold is 41.7% gold

Vermeil is sterling silver that has been gold-plated with 14kt or higher karat. Bali vermeil is generally plated with 24kt gold. The difference between vermeil, and gold-filled, is in the thickness of the gold and the base metal used. In vermeil, the base is sterling silver.

Gold-filled is also called rolled-gold. These beads and findings are not actually filled with gold. They are made of a base metal (usually brass or copper) covered by sheets of gold in a mechanical bonding process. The gold content is 5% or 1/20 of the total weight. Usually made with 14k gold, it is hard wearing. With reasonable care it will not peel or flake, and should last as long as solid 14k gold. It is safe for most people with sensitive skin. Gold filled is 10kt or higher karat over a base metal.

Gold-plated is a base metal such as steel or brass dipped into a bath of electroplating solution, with a lump of solid gold. When an electric current is applied, a thin layer of gold is deposited on the metal. Gold plate is 10kt or higher over base metal. The gold layer is less than gold filled, quite thin and will wear off faster than gold filled.

White gold is an alloy of yellow gold with other white metals, such as zinc, nickel, platinum and silver. White gold is durable and resistant to tarnish or firescale but it is brittle and requires platinum or rhodium plating. Once the plating wears off, it can cause allergic reactions. It is generally produced to be a more cost effective substitute to platinum. Traditionally nickel was used in white gold. However, nickel is no longer used as it can cause reactions with some people.

Rose Gold is alloy copper with gold, generally 75% gold and 25% copper. By altering the different percentages of each, the intensity of rose gold will be lighter or darker. Because of the copper content, rose gold will patina over time.

Silver Category

Fine silver is .999 pure silver, which is generally very soft and easily bent.

Sterling silver is .925 silver and .075 alloy, usually copper. In order to be called sterling silver it must have .925 silver but the .075 alloy can be any other metal. Because of the addition of copper, sterling silver will tarnish and is prone to firescale. However, it is the copper alloy that gives the silver strength

Silver plate is a thin layer of fine silver over a base metal which wears off easily.

Bali silver is sterling silver made in Bali, Indonesia. The beads and findings are characterized by fine granulation and detailed wire filigree designs. Items that are labeled "Bali-style" are generally made in India and can not be guaranteed as sterling silver.

Hill Tribe Silver ranges from 95-98% silver made by the Karen Hill Tribe in Thailand. The higher silver content in the metal makes it more malleable in creating the beads and findings. Themes are generally related to nature like leaves, flowers, and sea animals.

Indian silver is sometimes sterling silver or lower grade silver beads. Usually "Bali-style" beads are made in India and are generally less detailed than Bali beads.

Other Metals

Platinum is a heavy, malleable, ductile, precious, hypoallergenic gray-white metal, resistant to corrosion. It does not tarnish or firescale but because of its high melting temperature, casting and soldering is difficult. Platinum is extremely rare which accounts for its high market price.

Palladium is a rare silver-white metal of the platinum group. Palladium resembles platinum chemically and is primarily used as an industrial catalyst and in jewelry.

Rhodium is a rare silvery-white hard metal. Rhodium is a member of the platinum group, is found in platinum ores and is used in alloys with platinum. It is the most expensive precious metal. Rhodium is a metal very similar to platinum, sharing many of the properties of platinum including its white color. Rhodium plating is used to make white gold look whiter. The natural color of white gold is actually a light gray color. Rhodium is very white and very hard, but it does wear away eventually.

Titanium is a natural element which has a silver-gray-white color. Titanium is the hardest natural metal in the world. It is very strong, three times the strength of steel and much stronger than gold, silver and platinum but yet is very light weight. Pure titanium is also 100% hypoallergenic which means that it if safe for anyone to wear.

Copper is a reddish gold metal that patinas to a warm brown but can also take on a nice green patina with oxidation

Brass is a copper and zinc alloy in gold color. It will tarnish and turn brown overtime

Nickel is a white metal that looks like silver but can cause allergic reactions in some.

Pewter is a tin alloyed with other metals and is gray silver in color. Pewter beads and findings may sometimes be mistaken for antiqued/oxidized silver. Older pewter beads and findings sometimes contained lead.

Niobium is a very strong gray metal that is anodized to bright colors. It is hypo allergenic

Surgical steel is iron, carbon, chromium and various other base metals and may sometimes contain nickel.

German silver is copper, zinc and nickel that looks like silver but contains NO silver. It is known as nickel silver.

Innovative Metals

Argentium silver, invented in 1996 by Peter Johns, like sterling silver is at least .925 pure silver. Unlike sterling which is 0.75 alloy copper, argentium has a small amount of germanium instead of copper. It is free from tarnish and firescale, more malleable, easily fused and fired with metal clay. Germanium is an element similar to tin and silicon.

Platinum silver was created by American Bullion Precious Metals in Carson, CA in 2003. It has three formulas all beginning with .925 sterling and 1%, 3.5% or 5% platinum. This metal is a cheaper alternative to white gold. This new alloy can be fabricated and cast more easily than platinum and is tarnish/firescale resistant. Platinum is a white metal, but unlike gold it is used in jewelry in almost its pure form (approximately 95% pure).

Platinum is extremely long wearing and is very white, so it does not need to be rhodium plated like white gold does. Platinum is very dense and heavy metal.

Precious Metal Clay PMC is a metal compound developed in the early 1990s in Japan by metallurgist Dr. A. Morikawa. The material consists of extremely fine precious metal powder in a colloidal suspension, which burns of on firing. Success was first achieved with gold, and later duplicated with silver. The material is modeled into the desired shape, and then kiln-fired; which burns off the carrier, leaving only the pure metal. Shrinkage from 8 to 20% occurs (depending on the variety used). Once the clay is worked, then dried, it is fired in a kiln or with a hand-held torch. The binder burns away, leaving just the precious metal, and the object is smaller because the binder has been removed. Another brand, Art Clay Silver (ACS) has similar properties.

Lisa Kan is a glass bead artist, jewelry designer and writer. As an avid researcher and bead purveyor, she hopes to share her knowledge about beads through her writings. Look for her first book, Bead Romantique, published by Interweave Press to be released April 2008. Her book is available for pre-ordering on Amazon.com and Interweave Press. You may view more of her work on her website, www.LisaKan.com or email comments about this article to LisaKanDesigns@yahoo.com