The measurements for gemstone market are in the metric system.
Weight conversion: (Avoirdupois)
1 ounce = 28.349 grams
1 pound = 453.5 grams
2.20 pounds = 1 kilogram (kilo)
1 kilo = 1000 grams
1 kilo = 5000 carats
1 gram = 5 carats
To convert ounces to grams: Multiply ounces by 23.349 to get the number of grams.
To convert grams to ounces: Multiply grams by .0353 to get the number of ounces.
To convert pounds to grams: multiply pounds by 453.59 to get the number of grams.
To convert pounds to kilograms: multiply pounds by 0.453 to get the number of kilograms.
In the precious metals market the following weights are used.
One Troy pound = 12 troy ounces
One troy oz = 20 pennyweight
One troy oz = 480 grains
One troy oz = 33.3 grams
One pennyweight = 24 grains
Formula to convert grams to pennyweight: Multiply grams .6006006 by to get the number of penny weight.
Formula to convert grams to Troy Ounces: Multiply grams by .03003 to get the number of Troy Ounces.
1mm = 1/25th of an inch
10mm = .39 inches
Weights we liked
Grain: A basic unit of measure in the British system, originally based on the weight of a grain of barley.
7 pounds = 1 clove
14 pounds = 1 stone
28 pounds = 1 tod
264 pounds = 1 sack