The Gran Full Spectrum Colorimeter DC2000fs by Gem Instruments.  Manufactured in Israel by Gran Computer Industries Ltd., the Gran diamond colorimeter uses full spectrum analysis to color grade loose, mounted and rough diamonds from 0.25 to 10 carats. 

What the industry has been aware of for some time, but hasn't shared with the general public is something called "Color Typing".  The Gran Full Spectrum Colorimeter DC2000fs, introduced in the spring of 1999, is a wonderful gemological color grading device.  With this machine, at Samuel Gordon Jewelers we can actually show that not all F, G or H color diamonds are the same.  Our Gran DC2000fs colorimeter is so precise we can now actually break down each color grade into five color types.  Instead of asking someone what color a diamond is, you can ask about the diamond's color and type.  For example, an G color can be an G1, G2, G3, G4 or G5 (G1 being the best borderline F and G5 is a borderline H color).

On the GIA grading scale, the Gran Diamond Colorimeters measure from D through fancy intense with an accuracy of 1/2 of a color grade.  They also indicate the tints and hues of the stone. Although typically unaffected by fluorescence or phosphorescence, the colorimeters features a built in 365 nm UV light source for fluorescence testing.

Colorimeter specifications:  The Gran Diamond Colorimeters are portable and run on 100-240 Volts AC, 50-60 Hz.  The grading lamp has a minimum life of 1000 hours and is easily replaceable.  Dimensions: 6" x 10.5" x 5".  Weight 5.3 lbs.  This full spectrum colorimeter is one of the many ways we continue to provide the best service and jewelry technology in Oklahoma.