Gold carat
The purity of gold is determined by the karat measurement unit. The grade is measured using the following relationship, the highest value of which is 24.
If we divide a piece of gold into 1000 pieces and out of that 1000 pieces are 750 pieces of gold, we conclude that the piece has a carat value of 750 from 0 to 1000, which is 18 because if 18 is divided by 24 divide and multiply the result by a thousand, the number 750 is obtained.
The most common carats used for gold are listed in the table below. Usually, the lowest purity of gold is defined as 10 carats, although gold with less than 10 carats as well as 22 and 23 carats are also made.
| Carat | Ratio of gold to other metals | percentage of gold |
| 24 | 24 | Pure |
| 18 | 6 to 18 | 75 |
| 14 | 10 to 14 | 58.3 |
| 12 | 12 to 12 | 50 |
| 10 | 10 to 14 | 41.7 |
