Bleaching is a treatment used to lighten or remove color of a porous gem, it could include heat, light or chemicals.
Coating is a method of enhancement that can vary widely. A gemstone may be coated to protect dye treatments; to improve appearance; provide color or add other special effects.
Treatment This is a gemstone treatment that alters the color of stones through a combination of chemical exposure and heat treatment. FTC requires that diffusion be disclosed on gemstones in advertising.
The introduction of coloring matter into gemstones to give them new color, intensify color and/or improve color uniformity.
Filling surface-breaking fractures or cavities with a glass, plastic, solidified borax or other substances to improve clarity, appearance, stability, or add weight to a gem.
Heating is an enhancement treatment used for centuries to change the color of various materials. The use of heat can effect color, clarity or phenomena.
High Temperature, High Pressure (HTHP)
Application of heat and pressure combined to effect alteration of color, clarity and or phenomena.
When a porous gemstone is permeated with a polymer, wax or plastic to give it greater durability, and improve its appearance.
The use of neutrons, gamma rays or beta particles to alter a gemstones color. May be followed by a heat process.
The surface of a porous opaque or translucent gemstone is impregnated with a colorless wax, paraffin or oil to improve its appearance.