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. cabochon) and dimensions. These calculations include special functions for diamonds.
| Metal SPOT PRICES | |||
| Metal | ($/gram) | ($/troy_oz) | |
| Gold | $65.723 | $2044.21 | |
| Platinum | $30.029 | $934.01 | |
| Palladium | $32.601 | $1014.0 | |
| Silver | $0.808 | $25.13 | |
| Updated every Two Minutes | |||
METAL AND ALLOY PRICING:
- Jeweler's Buy Price of Gold Alloy : This calculates the Gold Alloy Value which is the price that the jeweler can pay for scrap based on the current spot price of gold, the weight of the gold alloy, purity of the alloy (karat), the refiner's fee, and the jeweler's profit (fee).
- Jeweler's Buy Price of Alloy: This calculates the Precious Metal Alloy Value which is the price that the jeweler can pay for scrap based on the type of metal (gold, platinum, palladium, silver), the current spot price of the refined precious metal, the weight of the alloy, purity of the alloy (% pure), the refiner's fee, and the jeweler's profit (fee).
- Junk and Clad Silver Coin Value: The compute the Value of Junk Silver (90%) and Silver Clad (40%) Coins based on the spot price of silver and the face value of the junk and clad silver coins.
GEM CARAT (Weight) ESTIMATES:
- Round Faceted: This computes the Carat Weight of a Round Faceted Gem base on the gem type (e.g. emerald) and the dimension.
- Pear or Teardrop: This computes the Carat Weight of a Pear or Teardrop shaped gem based on the gem type (e.g. Agate) and the dimensions.
- Cabochon: This computes the Carat Weight of a Cabochon cut Gem based on the gem type (e.g. Alexandrite) and the cut dimensions:
- Cushion Faceted: This computes the Carat Weight of a Cushion Faceted cut Gem based on the gem type (e.g. Amethyst) and the cut dimensions.
- Heart Shape Faceted: This computes the Carat Weight of a Heart Shaped Faceted cut Gem based on the gem type (e.g. Andalusite) and the cut dimensions.
- Emerald Cut Faceted: This computes the Carat Weight of an Emerald Cut Faceted Gem based on the gem type (e.g. Aquamarine) and the cut dimensions.
- Long Rectangular: This computes the Carat Weight of a Long Rectangular cut Gem based on the gem type (e.g. Blue Topaz) and the cut dimensions.
- Navette or Boat-shaped: This computes the Carat Weight of a Navette or Boat-shaped Gem based on the gem type (e.g. Cats Eye) and the cut dimensions.
- Square Cut Faceted: This computes the Carat Weight of a Square Cut Faceted Gem based on the gem type (e.g. Onyx) and the cut dimensions.
- Marquise Faceted: This computes the Carat Weight of a Marquise Faceted Gem based on the gem type (e.g. Precious Topaz) and the cut dimensions.
- Oval Faceted: This computes the Carat Weight of an Oval Faceted Gem based on the gem type (e.g. Sapphire) and the cut dimensions.
- Specific Gravity: This returns the Specific Gravity of any Gem based on the type of gem (e.g. Tanzanite).
DIAMOND CARAT (Weight) ESTIMATES:
These are carat weight estimations specifically for diamonds.
Common Diamond Cuts
- Round Brilliant: This computes the Carat Weight of a Round Brilliant diamond based on the cut's dimensions.
- Oval Brilliant: This computes the Carat Weight of a Oval Brilliant diamond based on the cut's dimensions.
- Heart Shaped: This computes the Carat Weight of a Heart Shaped diamond based on the cut's dimensions.
- Emerald Cut: This computes the Carat Weight of a Emerald Cut diamond based on the cut's dimensions.
- Baguette: This computes the Carat Weight of a Baguette diamond based on the cut's dimensions.
- Princess Cut: This computes the Carat Weight of a Princess Cut diamond based on the cut's dimensions.
- Triangular Brilliant: This computes the Carat Weight of a Triangular Brilliant diamond based on the cut's dimensions.
- Marquise Brilliant: This computes the Carat Weight of a Marquise Brilliant diamond based on the cut's dimensions.
- Pear-shaped Brilliant: This computes the Carat Weight of a Pear-shaped Brilliant diamond based on the cut's dimensions.
- Tapered Baguette: This computes the Carat Weight of a Tapered Baguette diamond based on the cut's dimensions.
- Old European: This computes the Carat Weight of a Old European diamond based on the cut's dimensions.
- Cushion: This computes the Carat Weight of a Cushion diamond based on the cut's dimensions.
General Instructions
Precious Metal Buy Price Instructions
- The jeweler ascertains which precious metal is in the scrap (platinum, gold, palladium or silver).
- The jeweler ascertains the purity as either a karat (k) or percentage. Karat values are converted to percentages inside the Jewelers calculator automatically.
- The jeweler weighs the scrap. The Jeweler calculator accepts the most common weight units including grams and troy ounces.
- The jeweler enters the cost of refining as a percent of the transaction (e.g. 5% refinement fee)
- The jeweler enters the desired profit as a percent of the transaction (e.g. 12% profit).
- The jeweler calculator will then use these factors along with the most recent spot price for the precious metal to calculate the price the jeweler should be willing to pay for the scrap precious metal based on a spot price that is up to date within the last two minutes.
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 .
Gem Carat Estimates
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, cabochon, princess cut, Cushion cut, Old European cut.
Diamond Carat Estimates
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.
APPLICATIONS
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.
AUTHORITATIVE SOURCE
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.