Understanding Gold Purity
Gold purity is a fundamental concept for anyone interested in buying, selling, or investing in gold. Pure gold (100% gold) is too soft for practical use in jewelry and many other applications, which is why it's typically alloyed with other metals to increase durability.
Gold Purity Measurements
There are several systems used worldwide to measure and express gold purity:
| Karat | Gold Content (%) | Parts Pure Gold | Common Uses |
|---|---|---|---|
| 24K | 99.9% | 24 out of 24 parts | Investment gold, gold bars, coins |
| 22K | 91.7% | 22 out of 24 parts | High-end jewelry, wedding rings |
| 18K | 75.0% | 18 out of 24 parts | Luxury jewelry, engagement rings |
| 14K | 58.3% | 14 out of 24 parts | Everyday jewelry, durable pieces |
| 10K | 41.7% | 10 out of 24 parts | Affordable jewelry, minimum legal standard in US |
Millesimal Fineness
Another system for measuring gold purity is millesimal fineness, which expresses purity in parts per thousand. For example:
- 999 = 99.9% pure gold (24K)
- 916 = 91.6% pure gold (22K)
- 750 = 75.0% pure gold (18K)
- 585 = 58.5% pure gold (14K)
Gold Hallmarks
Many countries require gold jewelry to be hallmarked with its purity level. These marks are typically small stamps that indicate the karat or millesimal fineness of the gold. Familiarizing yourself with these hallmarks can help you verify the purity of gold items.