Treatment
Annealing
Controlled heating and cooling modifies color centers.
Disclosure & care
Gemstone treatments
How treatments work, why they are used, and what they can mean for care, identification, disclosure, and value.
Treatment
Clarity enhancement with oil or resin
A treatment in which a substance enters surface-reaching fractures to reduce their visual prominence.
Treatment
Diffusion treatment
A high-temperature process that introduces coloring elements at or below a gemstone’s surface.
Treatment
Dye treatment
Foreign colorant alters apparent bodycolor or concentrates in pores and fractures.
Treatment
Fracture filling
A treatment in which material enters surface-reaching fractures to reduce their visual prominence.
Treatment
Heat treatment
Controlled heating used to alter or improve certain gem properties; effects and disclosure requirements depend on the material and process.
Treatment
HPHT color treatment
High-pressure, high-temperature annealing modifies Diamond color-related defects.
Treatment
Irradiation
Exposure to radiation to create or alter color, sometimes followed by heating.
Treatment
Laser drilling
Laser-created channels improve the visibility of selected dark inclusions.
Treatment
Lead-glass fracture filling
A clarity treatment in which a glass-like material fills surface-reaching fractures in ruby.
Treatment
Smoke treatment
Carbon-bearing smoke products darken porous gem material.
Treatment
Stabilization or impregnation
Polymer, resin, wax, or related material consolidates pores or weak structure.
Treatment
Sugar-acid treatment
Sugar impregnation followed by acid carbonization darkens porous Opal.
Treatment
Surface coating
A foreign surface layer masks or introduces color.