1, test results. It's a natural emerald, not a synthetic emerald.
2. Number of layers. The number of emerald layers in the range of 1-5 carats is mostly 2-3, and that in the range of 5- 10 carats is generally 3-4.
3. shape. The classic cut of emerald is octagonal rectangular cut. The reason is that emeralds are brittle, and cutting can avoid the "collapse" of gems.
4. color. The GRS certificate divides colors into green, bright green and bright green *. In terms of color, bright green * is what we often call "wood left color", which is the highest grade of jade color assessed by GRS certificate.
5. Place of origin. Gem laboratory will test the origin of gemstones according to their contents or properties, and indicate it on the certificate. For emeralds, Colombia is the most recognized place of origin in the mainstream market. The market price of the same quality emeralds in Colombia will be slightly higher.
The extended data CEC classifies the colors of emeralds into five grades according to hue, saturation and lightness:
1, crystal green, a light emerald, usually has a good fire color.
2, green green, medium color emerald.
3, bright green is bright green, with bright green, which is a relatively high-quality emerald color.
4. Thick green is thick green, and green is the strongest.
5. The top emerald color of fancy green is not the quality that can be achieved by market circulation goods, so it is not common.
Baidu Encyclopedia -CEC (Colombian Emerald Certificate)