Today, the precious metals that are used most often in the jewelry-making process are gold, silver, platinum, palladium and rhodium.
Gold
For use in jewelry, 24k (pure) gold is alloyed with other metals because it is so soft. Based on the percentage of gold in the mixture it is marked as 18k, 14k or 10k. The mixing in of other metals, i.e. copper or silver, will also have an effect on the final color of the gold jewelry.
When gold is mined from the ground it is a reddish-yellow color, so to craft white gold jewelry, the precious metal must be alloyed with white metals such as silver, palladium and nickel to give it more of a whitish color. White gold jewelry is always plated with rhodium, which is a metal in the platinum family, to give it the crisp, bright white color of platinum.
The name comes from the Spanish word platina, meaning "little silver." It is a dense precious metal that comes out of the ground in its beautiful silvery-white color and is more rare than gold. Platinum is hypo-allergenic and therefore perfect as an alternative when someone is allergic to the alloys that are mixed with gold. It is also the most popular metal choice for engagement rings.
Also considered a precious metal, silver has a bright white color that has been popular for use in jewelry, coins and ornaments throughout the ages. Most silver jewelry is crafted using sterling silver, also known as 925 silver, which is 92.5% silver and 7.5% alloy, often copper.
Also a precious metal, palladium is grayish-white in color and is often alloyed with gold to produce white gold. Palladium is more rare than gold or platinum and is therefore more expensive.
Even more rare than palladium, rhodium is the most valuable of all the precious metals. It is silver-white in color and highly reflective. In jewelry applications rhodium is used to plate white gold to give it the bright white color and brilliant shine. Black rhodium is sometimes used to plate gold or sterling silver jewelry to give it a blackened edgy look. Black rhodium is a combination of rhodium, other metals and chemicals.
