Gold

Gold has been treasured for thousands of years and is almost synonymous with riches. Durable yet malleable it has been fashioned into art objects and jewelry pieces from ancient times. In its pure form gold is rich yellow color and very dense and heavy. It can be polished to a very high luster.

Pure gold is quite soft. For jewelry purposes, gold is usually mixed or "alloyed" with other metals to give it strength and to change its color. Pure gold is stated as 24 Karat or 24K, and is often combined with other metals such as copper, silver and nickel to yield different purities such as 10K, 14K and 18K. 10K is 10/24 pure or 41.66% gold. 14K is 14/24 pure or 58.33% gold. 18K is 75%.

Using more nickel in the alloy will turn the metal white- using more copper will cause the metal to retain more of its yellow coloration. Variations in the alloy mix can create an interesting array of colors including pink and green.

White gold is often electro plated with another rare white metal, rhodium, in order to give it a very bright white finish. Base metals are often electroplated with pure gold to give the appearance of pure gold.

Federal Trade Commission rules require that jewelry items that are sold as gold must be stamped with the purity and bare the trademark of the manufacturer. The stamp will normally appear as 14K, or 18KT. Sometimes the stamp will take the numerical and take numerical form such as "585" indicating 14K, "750" for 18K.

Platinum

Platinum is a rare white metal that is relatively new to the jewelry world. It gained popularity in the early 20th century and has experienced a tremendous resurgence in the past 20 years. Platinum is also alloyed with other rare metals such as iridium and palladium giving it exceptional strength and durability. The purity of Platinum in jewelry is normally at least 90%. Platinum that is 95% or greater in purity can be stamped simply, PLT or PLAT. For purities below 95% the percentage must be indicated, such as "900 PLT", indicating a purity of 90% platinum.

Platinum is scarcer and more costly than gold and is used in greater purity as a jewelry metal. As a result jewelry items manufactured with platinum are considerably more expensive than those made from white gold.

Practical advice:

14K white gold is a very good alternative to platinum. The look is essentially the same and the price significantly less. Larger items made in platinum can also become quite heavy and may not be as comfortable as the same item in 14K white gold.

In items that contain expensive diamonds or gemstones, the cost of a platinum setting may be a relatively small portion of the overall cost. In these cases many customers prefer to have a platinum setting for the additional purity, heft, strength and durability.

Sterling Silver

Pure silver is a fairly soft metal and is mixed with other metals, usually copper, to attain greater hardness and durability for use in jewerly and flatware. Sterling silver contains 92.5% pure silver and 7.5% alloy. Sterling silver is often expressed and stamped as .925.

Silver is the most reflective of all metals. For this reason it is used as the backing for mirrors. It's ability to take a very high polish and its malleability and durability make it a great metal for jewelry making. It's relative availability compared to gold and platinum make it an affordable precious metal.

Sterling silver has a tendency to oxidize in air, causing it to darken. To look it's best it needs to be polished from time to time in order to retain its luster. Polishing clothes are available that with gentle rubbing can quickly remove the oxidation and restore a bright finish. Sealers are also used on some silver products to provide tarnish resistance.