The Jeweler's Calculator accurately calculates the carat weight of gems and the current value of precious metals including alloys of different purity. Gem weights are based on the gem type (e.g. ruby), their shapes (e.g.) and dimensions. These calculations include special functions for diamonds.
|Metal SPOT PRICES|
|Updated every Two Minutes|
METAL AND ALLOY PRICING:
GEM CARAT (Weight) ESTIMATES:
DIAMOND CARAT (Weight) ESTIMATES:
These are carat weight estimations specifically for diamonds.
Common Diamond Cuts
The Buy Price: Gold Alloy equation is only for gold and only allows the purity to be entered as a karat (k). The Buy Price: All Alloy lets the jeweler select the precious metal (platinum, gold, palladium and silver) and accepts the purity as a percentage.
The precious metals currently include: gold, platinum, palladium and silver
For Junk Silver: The Junk Silver Value function computes the value of U.S. silver coins without numismatic value. The formula lets you enter the face value of the silver coins and uses a 0.715 factor and the SPOT price of silver to compute the current value .
The equations for diamonds and gems provide the approximate carat weight of a gem based on its shape and dimensions. These equations approximate the volume of the gem and use the specific gravity to provide a karat weight estimate. The different weight approximations are based on the shape of the gem (see list of cuts below). The vCalc library containing these equations is under Earth Science / Mineralogy / Gemology.
The gems include: Agate, Alexandrite, Almandite garnet, Amethyst, Aquamarine, Beryl, Bloodstone, Blue topaz, Carnelian, Cats eye, Chalcedony, Chrysoberyl, Citrine, Corundum, Demantoid garnet, Diamond, Emerald, Golden beryl, Green beryl, Kunzite, Lapis lazuli, Morganite, Onyx, Opal, Precious topaz, Pyrope garnet, Quartz, Rose Quartz, Ruby, Sapphire, Sardonyx, Smokey quartz, Spessartite garnet, Tanzanite (zoisite), Topaz, Tourmaline, Tsavorite garnet, Turquoise, Yellow topaz, Zircon.
The gem cuts include: round (circular), oval, emerald cut, long rectangular, square, navette or boat-shaped, pear-shaped or teardrop,, princess cut, Cushion cut, Old European cut.
The Diamond Weight tab contains carat weight equations that are specific to diamonds and diamond cuts.
NOTE: Never use an estimating equation for the weight of a gem if you can weigh it on a quality jeweler's scale. These equations are useful when the jeweler is trying to preserve the setting of the gem while still providing a carat weight estimate. In this way, the jeweler can ascertain the type of gem, its shape and then using precise measuring tools measure the salient dimensions for use in these equations. These steps can be done while the gem remains in the setting.
The vCalc Jeweler's calculator is free to use like all the other equations and calculators found in vCalc. Please feel free to comment on this wiki page using the comment button below and help us make a better Jeweler calculator for you.
The vCalc Jeweler's Calculator provides Jewelers and other merchants of gems and precious metals to compute an estimated current market value for jewelry items. Likewise private owners and insurance providers can make similar estimates for use in establishing the basis for insurance valuation and coverage.
The equations and data used in vCalc's jewelry library and calculator were reviewed by a certified gemologist. The equations are based on industry recognized formulas and data. The table below shows a comparison of computations between vCalc and an industry accepted application (Quantum Leap).
The length, width and depth are in millimeters (mm), and the Quantum Leap and vCalc measurements are in carats (cwt).
The largest variance, an oval faceted alexandrite, which can be seen in the last row above, has been double checked against several source equations which tend to support vCalc's accuracy.