A new device can color-grade both fancy colored diamonds as well as diamonds with secondary hues, says a release from manufacturer ImaGem.
The device uses data from thousands
of samples to derive its grades for fancy colored stones, says Dr.
Lalit K. Aggarwal, chairman of ImaGem, which manufactures the device.
The device, called the GL3200,
can “identify which stones have brown or gray or other hues and then
map those on a D through Z scale using scientific measurement
technologies,” says Aggarwal, who says he worked on the secondary-hue
issue for 20 years. “We now have a scientific method of determining the
secondary hue. A lot of different opinions are getting resolved with
The machine can grade 2,400 diamonds a month,
the company said, and also rates fluorescence, light behavior,
proportion analysis, symmetry, and alignment for round as well as fancy
shapes. Diamonds are loaded into the machine by a robotic arm.