The premium grade gemstone weight calculation tool from the authors of the award-winning Crystal Guide Pocket Edition app. Gem Carat Weight Calculator allows fast, accurate weight calculations to be performed by taking a few simple measurements for diamonds, sapphires, emeralds and 300+ other crystals. By combining industry standard formulae with our comprehensive array of gemstones and facets/cuts data, we are able to bring you an app that performs accurate calculations efficiently, right from your pocket. In addition to calculating weights, the app also has a thorough A-Z list of browsable gem data (300+ profiles), including the ability to directly compare them. FEATURES: Calculates gemstone carat weight, gram weight and tolerance value ranges. Contains 300+ gemstones and over 60 facet/cut types. Browsable A-Z list of crystals, gemstones and minerals, each with its own image and complete geological profile. Glossary of mineralogical terms and definitions. Reference charts. Directly compare gemstone profiles. Unit conversion tool. Full history of calculations for fast consults. Free database updates.