The purity of gold is measured in karats. If gold is 100% pure, then it is 24 karat gold (24K). In its pure form, gold is soft and malleable, but scratches easily and is unsuited for jewelry wear. Consequently, it must be alloyed with other metals to give it strength.
- 18K Gold - 18 parts gold, 6 parts other metals by weight (75% pure)
- 14K Gold - 14 parts gold, 10 parts other metals by weight (58.3% pure)
- 10K Gold - 10 parts gold, 14 parts other metals by weight (41.7% pure)
The shade of yellow gold can vary based on the alloy. As the amount of gold increases, so does the brightness of the yellow color. When yellow gold is mixed with nickel and zinc, it becomes white gold, which looks similar to platinum.
Made from yellow gold and various alloys and is not a true white metal. It is often plated with Rhodium, a white and reflective metal that provides an excellent protective coating. Rhodium plating will gradually wear off and require re-plating.