Many different types of metal components are used in making jewelry. Below is an explanation of the many terms you'll find on this site, as well as information about metals in general.

Base Metal is a catch-all term for any metal that is not one of the noble or precious metals. Examples include iron, steel, copper, brass, nickel, lead and tin.

Brass is an alloy of 70% copper and 30% zinc. It has a sharp yellow-gold tone.

Copper is a native element (found pure in nature) with a reddish-orange color.

Gold is a noble and precious metal, as well as a native element (found pure in nature). Because it is very soft and malleable, almost all gold used in jewelry is alloyed with secondary metals to enhance durability. The purity of gold is measured in karats (kt), expressed as a ratio of 24 parts. For example, 24 kt is 100% pure gold; 22 kt is 91.7% pure gold; 18 kt is 75% pure gold; 14 kt is 58% pure gold; and 10 kt is 41.6% pure gold. Depending on the color of the gold, the other parts may be copper, silver, nickel, zinc, tin, palladium and/or manganese. The higher the gold content, the brassier the color.

Yellow Gold is the most common color of gold. It is usually alloyed with silver and copper.

White Gold is harder than yellow gold with a bright lustrous white color. It is usually alloyed wit palladium, a rare and expensive precious metal, so white gold is more expensive than yellow gold.

Rose Gold has a pink to reddish tone. It is mostly alloyed with copper.

Gold Fill, also called gold overlay, is made by using heat and pressure to apply a layer of karat gold (usually 10 kt) to a base of less costly metal. The gold must be at least 10% of the total weight of the item. Gold fill is 50 to 100,000 times thicker than gold plate.

Gold Plate is a very thin layer of gold that is electroplated or electrochemically applied to a base metal. The total gold content of the object may be less than 5%.

Vermeil is a French term for 22 kt gold plate over sterling silver.

Gunmetal is a black nickel plating over base metal. It has a dark steely-gray hue.

Niobium is a nickel-free metal alloy that is available in a variety of colors. It is anodized, which means it is colored by dipping it into an electrically charged bath. The amount of current determines the color.

Noble Metal refers to any of several metallic chemical elements that have outstanding resistance to oxidation, even at high temperatures. The grouping is not strictly defined but usually is considered to include rhenium, ruthenium, rhodium, palladium, silver, osmium, iridium, platinum, and gold.

Pewter includes any of the numerous silver-gray alloys of tin with various amounts of antimony (a metallic element) and copper. It takes on a dull silver-gray tone.

Platinum is a noble and precious metal, as well as a native element (found pure in nature). It is 60 times rarer than gold, found in only a few locations worldwide. It has a grayish-white color.

Precious Metals are metallic elements of high economic value. They include gold, silver, platinum and palladium.

Rhodium is a noble metal that is often used as an alloying agent to harden platinum. It has a silver-white color and is highly reflective and tarnish resistant.

Silver is a precious metal and a native element (found pure in nature). Because it is very soft and malleable, it is often alloyed with one or more secondary metals for added strength and durability.

Sterling Silver contains at least 92.5% silver, combined with other metals. The most common sterling alloy is 92.5% silver and 7.5% copper.

Fine Silver is at least 99.9% pure silver.

Bali Silver refers to beads and findings (clasps, earwires, etc.) that are handmade on the island of Bali, with a distinctive style using granules and ornate wirework. Most Bali silver is sold as sterling silver, but it cannot always be guaranteed. The style of Bali work is often imitated in other countries, such as India, Turkey and Israel. This work is referred to as Bali Style, and is usually cast, as opposed to handmade. Bali silver is often oxidized to create depth and emphasize the designs.

Thai Silver refers to beads and findings (clasps, earwires, etc.) that are handmade by the hill tribes -- groups of ethnic minorities -- of Thailand. Thai silver is usually at least 95% silver and adorned with unique stampings.

Silver Fill is fairly new to the market. It is made by using heat and pressure to apply a layer of sterling silver to a base of less costly metal. The sterling must be at least 5% of the total weight of the item. The sterling layer is hundreds of times thicker on silver fill than on silver plate.

Silver Plate is a thin layer of real silver applied to base metal.

Surgical Steel is an alloy composed mostly of iron, carbon, chromium and nickel. It is often dubbed hypoallergenic, although it does contain about 8% nickel, which is a common source of allergy.

Titanium is a native element (found pure in nature) that is extremely strong, yet extremely lightweight. It is very popular for industrial use, including aerospace, medical and sports applications, but is fairly new to the jewelry industry. It has a grayish-white color and is tarnish resistant, as well as a good option for those with nickel allergies.

Resources for "About the Metals:"
Crystals, by Jennie Harding.
http://www.rings-things.com
http://www.thaigem.com
http://www.britannica.com
http://www.titanium-jewelry.com