Novice jewelers are taught the basics of the profession with specific examples. First you need to learn to distinguish stones, including diamonds, from each other, and then sort by weight. There are several ways to determine the weight of this gem.
Necessary
- - carat scales and sieve;
- - calculation tables.
Instructions
Step 1
With carat weights, you can determine the weight of a diamond, which is measured in carats. One carat is equal to 200 milligrams (1/5 gram). You can weigh such a diamond with an accuracy of the third decimal place. You must write down the weight up to the second digit, while the third digit is discarded, unless it is 9. Diamonds are divided into three groups according to their weight: large (from 1, 00 carats and more), medium (from 0.30 to 0, 99 carats) and small (up to 0.29 carats).
You can weigh several diamonds at once. Scatter the small ones through a set of sieves into size groups, and then use the scales again, placing the entire group of stones on the bowl. This sorting method is used when stones are sold by size.
Note: In the documents on stones, when crushing or combining lots, some change in the indication of the mass of the lot is possible. Thus, the indicated weight of the diamond may not exactly correspond to the real one. But don't forget that jewelers are people too.
Step 2
Often times, a diamond is set into a piece of jewelry, which means that its exact weight cannot be determined until the stone is removed. Always weigh the stone before the framing. Set diamonds (their weight) are measured using calculation formulas. The mass of a standard round cut diamond should be calculated as follows:
M = D2xHx0, 0061
where: D - diameter, H - height, M - carat weight.
If the rudist is thick, the coefficient will vary from 0, 0061 to 0, 0067, depending on its thickness. The error in calculating the weight according to the presented formulas is about 10% for diamonds of the correct cut, for stones with a distorted cut, as well as ancient and non-standard ones, the percentage of errors in measurements increases.
Step 3
Use special tables that indicate the weight of the stone, based on its dimensions. Determining the mass of a stone from a table of diameters gives a very inaccurate weight value. This method also requires measuring the diameter of the diamond.
