Precious Metals Information

Facts about Precious Metals used in Jewelry

Traditional metals used in jewelry are the “noble metals”: silver, gold and the platinum metal group (including platinum and palladium). Noble metals are so called because of their ability to withstand corrosion and oxidation and their chemical stability. Today's jewelry is more varied and versatile than ever. This is partly due to the use of new types of metals and alloys used to make jewelry.

Through the use of alloys, two or more metals or elements can be combined to give the resulting metallic substance certain properties that are different from its component metals. The primary purpose of alloys in jewelry is to give metals more desirable characteristics. For example, pure gold (24 karat gold) is too soft for prolonged wearing and would scratch easily. Most gold jewelry is either 14 karat gold or 18 karat gold which consists of gold mixed with other alloys, usually silver, nickel, copper or zinc. Sterling silver is silver mixed with alloys to make it stronger. Sterling silver is 92.5% pure silver usually mixed with 7.5% copper.

Jewelry Classification Purity Noble Metal / Common alloys 24 karat (24k) gold 99.9% Pure gold 18 karat (18k) gold 75.0% Gold with nickel, copper or zinc alloy 14 karat (14k) gold 58.33% Gold with nickel, copper or zinc alloy 10 karat (10k) gold 41.66% Gold with nickel, copper or zinc alloy silver 99.9% Pure silver sterling silver 92.5% Silver with copper alloy

Figure 1. table of metal purities.

The table below highlights some of the characteristics of different metals used in modern jewelry:

metal recent price (per oz) Hardness level (Mohs scale) common alloys used Pros Cons 24k Yellow Gold $591 2.5 n/a brilliant luster too soft for most jewelry 18k Yellow Gold $591 2.75 silver, copper, zinc, nickel, palladium alloys used make gold more durable for everyday wear nickel alloy can have allergenic properites 14k Yellow Gold $591 3-4   alloys used make gold more durable for everyday wear nickel alloy can have allergenic properites White Gold $591 2.8-4.0 silver, palladium, nickel less expensive alternative to platinum can have allergenic properties; rhodium plating will eventually wear off Silver $11 2.5 copper low price point suseptible to scratches Platinum $1064 3.5 ruthenium, iridium, platinum hypoallergenic, will retain white color suseptible to scratches, prongs can bend Palladium $318 4.5 ruthenium, iridium hypoallergenic, maintains natural white color, great luster enhances gems, naturally strong metal, lighter than platinum suseptible to scratches, more sensitive to acids, won't take a high polish well Tungsten Carbide n/a 9.0 carbon hypoallergenic, low price point, maintains white color forever, looks great after years of wear not a precious metal, can chip or shatter, can oxidize Tungsten n/a 7.5 n/a hypoallergenic, resists scratches, especially useful for brushed jewelry designs not a precious metal Stainless steel n/a 6.5 carbon, iron resists corrosion and staining not a precious metal Titanium n/a 6.0 aluminum, iron, tin hypoallergenic, high tensile strength, resists corrosion, light weight suseptible to scratches

Figure 2. Table of precious metal characteristics.

 

Disclaimer: The information provided on this page is for informational purposes only. Metals prices are approximate prices as of October 2006 and do not constitute an offer to buy or sell at that price. No representation or warranty, either express or implied, is made with respect to this information.