The Metropolitan Museum of Art Store’s Colored Stones
Colored stones are offered in an array of different colors and styles. There are variations of color, variety, pattern and hue which may be used in our jewelry. Nearly all colored stones sold at jewelers or specialty retailers, including those sold at the Metropolitan Museum of Art Store, are enhanced or treated using various techniques. Many of these techniques have been used for centuries. The Metropolitan Museum of Art Store’s jewelry reproductions and adaptations utilize colored stones sourced through approved manufacturers with any or all of the following treatments and enhancements in accordance with acceptable industry standards.
Bleaching: The application of chemicals or other agents to lighten or enhance color consistency.
Coating: The use of wax, resin or oil applied to the exterior of a porous colored stone to protect the natural substance and improve appearance.
Diffusion: The use of high temperatures and chemicals to create or enhance color.
Dyeing: The act of adding coloring agents to enhance or alter color.
Heat Treatment: The application of heat to enhance the color and/or clarity of colored stones.
Infusion: The centuries old practice of filling a gem material with an oil, wax, glass, resin or other material, colored or colorless, to improve appearance.
Irradiation: The alteration of a stone's color through the use of radiation. This is often followed by a heating process.
Reconstituted Stones: The compressing and forming of small chips of colored stones with plastic resin and/or colorant to achieve color consistency, durability, and desired shape.
Additional Technologies: Techniques for enhancing colored gemstones, either detectable or otherwise, are continually being developed.