GemStone Care

Colored Gemstone Enhancement Processes

There are many methods of enhancing colored gemstones. We describe the most common enhancements below. For more information on colored gemstone enhancements, see the American Gem Trade Association’s Gemstone Information Manual.

Heat Treatment

The application of heat to enhance the color and/or clarity of gemstones has been a common practice around the globe for centuries. It is part of the standard polishing and finishing process for many colored gemstones. As such, it is accepted by the jewelry industry and the American Gem Trade Association. The enhanced color and/or clarity of heat-treated gemstones is permanent.

Infusion

The filling of a gem material with an oil, wax, glass, resin or other material, colored or colorless, to improve appearance. This process began centuries ago by gemstone merchants who found that immersing emeralds in oil or waxes made them look clearer to the unaided eye. This practice continues today with many colored gemstones.

Coating

The use of wax, resin or oil applied to the exterior of a porous colored gemstone to protect the natural substance, and to improve sturdiness and appearance.

Bleaching

The application of chemicals or other elements to lighten or enhance color consistency.

Dyeing

The act of adding coloring agents so that they permeate a colored gemstone to enhance or alter color.

Irradiation

The alteration of a gemstone’s color through the use of radiation. This is often followed by a heating process. The enhanced color of irradiated gemstones is permanent.

New and Future Technologies

Techniques for enhancing colored gemstones, either detectable or otherwise, are continually being developed. These may be difficult, or in rare cases, impossible to detect, even for the most sophisticated laboratory. Blue Nile will continue to work with industry groups and gemological experts who are committed to the identification and disclosure of new and future techniques in order to maintain our stringent quality standards.

Basic Gemstone Care

While gemstones are durable, they require varying levels of care. For example, some gemstones are especially vulnerable to household chemicals and temperature changes. Cleaning gemstones presents special challenges. While many gemstones should be cared for by following our basic care guidelines below, please refer to our Gemstone and Pearl Care and Enhancement Overview to understand the care requirements for your specific stone. If you still have questions, please contact Blue Nile customer service.

Cleaning

After removing your gemstone jewelry, clean it by following the directions on a non-abrasive jewelry cleaner. Make sure that the jewelry cleaner specifies that it is safe to use with your gemstone. Use a soft cloth to remove any remaining dirt or other residue.

Storing

Store your gemstone jewelry in a lined case or a soft cloth, so the gems do not touch each other or parts of other jewelry. Gemstones are harder than gold, silver, or platinum and can scratch the surfaces of your other fine jewelry if they are not kept separate.

Wear

While it’s true that gemstones such as ruby and sapphire are second only to diamond on the hardness scale, it is not a measurement of their indestructibility. It means that these gemstones are able to resist scratching almost as well as a diamond. Abrasive surfaces, harsh chemicals, and sharp blows can damage even the hardest gem. Your gemstone jewelry should be the last thing you put on when getting dressed and the first thing you take off at the end of the night. Store your gemstones carefully and they will be enjoyed for generations.

Gemstone and Pearl Care and Enhancement Overview

Gemstone 

Accepted Enhancements

Gemstone Care

AgateHeated or dyed to improve color.Basic Gemstone Care.
AmberHeated to improve color and clarity.Do not use ultrasonic cleaning. Avoid sudden temperature changes, chemicals, perfume, cosmetics, and hairspray.
AmethystHeated to improve color.Basic Gemstone Care.
ApatiteHeatBasic Gemstone Care.
AquamarineHeated to improve color and clarity.Basic Gemstone Care.
Black DiamondHeated or irradiated to alter color.Basic Gemstone Care.
Black OnyxDyed.Basic Gemstone Care.
Black SpinelNone.Basic Gemstone Care.
Blue TopazHeated and/or irradiated to alter color. Thermal coated to alter color.Basic Gemstone Care.
CarnelianHeated to improve color.Basic Gemstone Care.
ChalcedonyDyed.Basic Gemstone Care.
Chrome DiopsideNoneBasic Gemstone Care.
CitrineHeated to improve color.Basic Gemstone Care.
CoralCoated or impregnated with color less substances to improve surface uniformity or durability. Bleached or dyed to enhance color.Basic Gemstone Care.
DiamondNone.Basic Gemstone Care.
EmeraldInfused to improve clarity and/or color.Do not use ultrasonic cleaning. Avoid sudden temperature changes, chemicals, perfume, cosmetics, and hairspray.
Fire OpalNone.Do not use ultrasonic cleaning. Avoid sudden temperature changes, chemicals, perfume, cosmetics, and hairspray.
GarnetNone.Avoid sudden temperature changes.
IoliteNone.Do not use ultrasonic cleaning.
KunziteHeated or irradiated to improve colorDo not use ultrasonice cleaning. Avoid direct sunlight.
LabradoriteNone.Basic Gemstone Care.
LapisDyed.Do not use ultrasonic cleaning. Avoid sudden temperature changes, chemicals, perfume, cosmetics, and hairspray.
MoonstoneNone.Basic Gemstone Care.
MorganiteHeated to improve color and clarity.Basic Gemstone Care.
OpalCoated to alter surface consistency and durability.Do not use ultrasonic cleaning. Avoid sudden temperature changes, chemicals, perfume, cosmetics, and hairspray.
Pearl (natural and cultured)Bleached, dyed, polished and coated.Do not use ultrasonic cleaning. Avoid sudden temperature changes, chemicals, perfume, cosmetics, and hairspray.
PeridotNone.Basic Gemstone Care.
PrehniteNoneBasic Gemstone Care.
QuartzGreen/Lemon: Irradiated to improve color. Smokey: Heated to improve color. Blue: Dyed. Rutilated/Rose/white: None.Basic Gemstone Care.
RubyHeated and/or infused to improve color and clarity.Basic Gemstone Care.
SapphireHeated and/or infused to improve color and clarity.Basic Gemstone Care.
SpinelNoneBasic Gemstone Care.
TanzaniteHeated to alter color and clarity. Infused to alter color and clarity.Do not use ultrasonic cleaning and sudden temperature changes.
TourmalineIrradiated to improve color.Do not use ultrasonic cleaning and sudden temperature changes.
TurquoiseCoated or impregnated with color less substances to improve surface uniformity or durability.Do not use ultrasonic cleaning. Avoid chemicals, perfume, cosmetics, and hairspray.
White AgateNone.Basic Gemstone Care.
White TopazNone.Basic Gemstone Care.