Low-Cost Option
Silver is the least expensive of the three and a good choice for casual jewelry and large pieces - a cuff bracelet or a strand of silver beads, for example. Silver shines brightly when new, but equally lovely is the patina it develops over time - a kind of warm, weathered sheen. On the downside, silver is relatively soft and not suited to securely hold precious gems. Silver also tarnishes, but less so if the jewelry is worn frequently. A silver polishing cloth will easily restore its luster.
How Gold Becomes White
White gold is created by alloying yellow gold with such metals as nickel, copper, silver and zinc to get a white hue. In addition, white gold pieces are often covered with a thin plating of rhodium (one of the platinum group metals) to strengthen them and give them a whiter appearance. This finish wears off over time and the plating process may be repeated. White gold has the same properties as yellow gold - meaning that 18-karat white gold is 75% gold mixed with 25% other metals. It is highly reflective and is not subject to tarnish. It also is less expensive than platinum. On the negative side, white gold isn't as pure, rare or durable as platinum - and it sometimes displays a yellow undertone.
Precious Platinum Is Pure
In comparison, platinum is a white metal that is denser, heavier and stronger than gold. Platinum used for jewelry is much purer than gold. Measured in parts per thousand, platinum jewelry is typically 850-999 parts pure platinum (85%-99.9%), with the remainder made up of other metals. This purity makes platinum hypoallergenic. It is said that all the gold in the world would fill three Olympic swimming pools. However, all the world's platinum would only fill a few inches of one pool.
Graduate Gemologist, GIA
Certified Appraiser