Coloured stone professionals assess fine alexandrites by the extent of the colour change they display and by the quality of the red and green hues they show under different lighting conditions.
FIND A JEWELLER
Use your postcode to find a jeweller near you with GIA reports and GIA-trained staff.
FIND A REPORT
Verify the information on your report matches what is archived in the GIA report database.
What to look for
Colour change is the most important quality factor for alexandrite
The most-prized alexandrites show a strong colour change from bluish green in daylight and red to purplish red in incandescent light, with moderately strong to strong colour saturation.
Cut is one of the most important factors in appearance
Alexandrites are most often fashioned as mixed cuts, which have brilliant-cut crowns and step-cut pavilions. Alexandrite’s pleochroism makes it a challenge for cutters. When fashioning alexandrite, cutters orient the gem to show the strongest colour change through the crown.
Carat weight allows for precise measurements
Most fashioned alexandrites are small, weighing less than one carat. Larger sizes and better qualities rise in price dramatically: Fine-quality stones in sizes above 5.0 carats are very expensive.
Alexandrite Quality Factors: The Comprehensive Guide
Tips & Advice
1. If it seems too good to be true, it probably is.
Natural alexandrite is rare and valuable. An inexpensive gem with a strong red-green colour change is likely to be a synthetic or simulant.
2. Work with a jeweller you trust.
Judging the quality of alexandrite requires expertise. Look for gemmological credentials. A jeweller who knows and loves alexandrite will welcome the challenge to find one that’s right for you.
3. When in doubt, get a lab report.
For a significant purchase an independent laboratory report can confirm that the alexandrite you are buying is natural.
4. Don’t expect to be able to match alexandrites easily.
Creating pairs or suites of alexandrite for earrings, a three stone ring or a necklace is very challenging. Matching size, shape, colour and colour change is particularly difficult.