The "C" on a gold ring typically indicates the gold's purity, specifically its carat weight, in countries where "C" is used instead of "K" (karat). Therefore, "18C" means the same as "18K," signifying that the gold is 18 parts gold and 6 parts other metals. In the US, "K" is commonly used to denote gold purity while "C" (carat) refers to the weight of gemstones.
Gold Purity Explained
The "C" mark, when referring to gold, is about determining the ratio of pure gold to other metals in the jewelry. Pure gold (24C or 24K) is too soft for most jewelry applications, so it's alloyed with other metals to increase its durability and alter its color.
Carat/Karat Values and Their Meanings:
Here's a breakdown of common carat/karat values:
| Carat/Karat | Gold Purity (%) | Description |
|---|---|---|
| 24C/24K | 99.9% | Pure gold. Very soft and not suitable for everyday wear. |
| 22C/22K | 91.7% | High gold content, resulting in a rich yellow color. Still relatively soft. |
| 18C/18K | 75% | A good balance of gold content and durability. Often used in fine jewelry. |
| 14C/14K | 58.3% | More durable than higher karat gold. A popular choice for rings and other frequently worn jewelry. |
| 10C/10K | 41.7% | The minimum gold content legally allowed to be sold as gold jewelry in the United States. More durable but less valuable than higher karat options. |
Carat vs. Karat: Regional Differences
- Karat (K): Predominantly used in the United States to indicate gold purity.
- Carat (C): In some countries, "C" is used to denote gold purity, equivalent to "Karat". However, "carat" is internationally recognized as the unit of weight for gemstones, particularly diamonds.
Conclusion
When you see a "C" on a gold ring, it likely represents the caratage of the gold, similar to the karat system, indicating the gold purity level. Always verify the origin or manufacturing standards of the jewelry to confirm the intended meaning of the "C" mark.
