Everything in Gemology Tools Pro
GT Pro is software for gemologists, jewelry appraisers and gemstone enthusiasts. Version 10, for Mac and Windows, is in development.
Gemstone Reference
A gem reference that runs on your own computer.
Gemstone Database
Over 500 gem species and varieties, each with refractive index, birefringence, optic character, specific gravity, hardness, crystal system, cleavage, pleochroism, UV fluorescence, chemical composition and more. Double-click a gem to open its full Data Page.
Find a Gemstone
Nearly 2,000 species, varieties, trade names and misnomers. Search "Calcentine", for example, and GT Pro takes you straight to Ammolite.
Gemstone Photos
More than 1,000 gem photos, opened from each gem's record.
Inclusion Gallery
Over 425 inclusion photomicrographs organized by gem, from photomicrographers including John Koivula, John Huff and Barbra Voltaire.
Gemstone Spectral Images
Common absorption spectra to compare with what you see in a spectroscope, drawn for both prism and diffraction-grating instruments and searchable by gem or by color. You can show the red end on the left or the right.
Gemology Glossary
A glossary of gem and jewelry terms.
Identification
Narrow down an unknown stone using the properties you can measure.
The Gemstone Separator
Start with over 500 possibilities and enter up to 15 properties: color, optic character, refractive index, birefringence, specific gravity, pleochroism, UV fluorescence, transparency, luster, phenomena, magnetic response and more. Adjustable RI and SG ranges, color near hits and near-hit results keep you from ruling out the right answer.
Magnetic Response in Gems
Many gems respond to a strong neodymium magnet. GT Pro records each gem's magnetic response on its Data Page and in the Separator, so you can use it alongside RI and SG to identify a stone.
Specific Gravity Calculator
Weigh the gem in air, weigh it again in water, and the calculator gives you the SG. Enter several readings and it averages them for a more reliable result.
Calculated Birefringence
Enter your high and low RI and the Separator shows the calculated birefringence next to each candidate's, so you can quickly discard gems outside your range.
Example: a blue, transparent stone. Entering Blue and DR U+ narrows 525 gems to 14. Adding an RI of 1.80 / 1.75 and Transparent leaves 2, one of which is "Assembled Stones". A quick check that the stone isn't assembled leaves Benitoite.
Weight Estimation
Estimate the weight of mounted stones from their measurements.
Diamond Weight Estimator
Estimated weights for mounted diamonds in 18 shapes. An information window explains how to measure each cut and shows the formula used, so you can check the result yourself.
Colored Stone Weight Estimator
Estimated weights for mounted colored stones in 20 shapes, using each gem's specific gravity, with a weight correction factor for adjusting the result up or down.
Cabochon Weight Estimator
Estimated weights for mounted cabochons.
Carat Weight Charts
Reference charts of weights for common sizes of diamonds and colored stones.
Grading & Appraisal
Tools for everyday appraisal work.
NAJA Diamond Cut Grader
The National Association of Jewelry Appraisers has its own diamond cut grading system. It's a little complicated, and GT Pro makes it easy.
Round Diamond Recut Planner
Makes it much easier to plan the recut of a badly chipped round diamond.
Diamond Crown Angle Calculator
Work out a diamond's crown angle from its measurements.
Akoya Pearl Grader
If you use The Guide for pricing pearls, this grader follows its system.
Custom Piece Calculator
Work up a value for a custom-made piece of jewelry where you control all of the inputs, then copy the description to your word processor.
Unit Converter
Convert common gemology units.
Study
Exam practice and day-to-day organizers.
Gemology Review Quiz
Over 900 gemology questions, with a few about metals and jewelry. Good for review if you are working toward a gemology diploma or your Graduate Gemologist exam.
Calendar, Planner and Card File
Simple built-in organizers for keeping track of appointments and contacts.