As a consequence, unlike diamonds, emeralds do not have purity indexes. In contrast to colored resin injection, which denatures the stone, impregnation in fine oils is a legal technique that is often used to intensify the color or mask a portion of the inclusions. (For more information on cedarwood oil, please see our article www.gem-matrix.com/cedarwoodandemeralds
If you want an emerald from Colombia's Muzo mine, you must request a certificate: this mine only produces about 50 jewelry emeralds per week. These are extremely pure and in high demand.