Gemstone Treatments

The incomparable allure of natural gemstones is often augmented through various treatment methods. Nowadays, it's rare to find gemstones on the market that haven't undergone some form of modification. Many treatments occur during the raw crystal stage, making it challenging to determine the extent of enhancements applied to a specific gem. Our chart below outlines the typical treatments that various gemstones undergo. Interestingly, even within a single design, treatments can vary. For instance, among a collection of thirty topaz gemstones, while most may have undergone irradiation treatment, some pieces may remain untreated. These enhancements can significantly impact the value of precious stones, with the highest prices reserved for natural gems of exceptional quality that have undergone no enhancements beyond standard cutting and polishing.

Enhancement Overview

  • Jewellery Maker only sells genuine gemstones, many of which have been enhanced.
  • For most gems today, enhancements are commonplace.
  • The market place sets the values of both natural and enhanced gems
  • Since certain enhancements are undetectable or difficult to detect, assume that all items are enhanced unless it is stated from gemmological evidence otherwise or the item is a type for which enhancements are not typically used.

Enhancement Codes

The following chart explains the enhancement and treatment codes that you will see on our website and TV broadcast. They are derived from industry standard codes which we have amended for further clarification.

N = Natural (No enhancement)

Gems that are, according to best available information, untreated.

H = Heat only

Enhancement via heat only.

U = Diffusion

Enhancement by the diffusion of foreign elements into the crystal lattice of a gemstone.
Example: Beryllium-diffusion.

HP = Heat & Pressure

Enhancement via extreme heat and pressure. Also referred to in the industry as HPHT (High Pressure High Temperature)

F = Filling

Enhancement by filling a gemstone's cracks and crevices with a colourless substance. Fillers include, but are not limited to, glass, plastic, resin, wax, and oil.

FD - Filling & Dye

Enhancement by filling cracks and crevices with a coloured substance. Fillers include but are not limited to, glass, plastic, and resin.

D = Dyeing

Enhancement by the introduction of a colouring agent into a porous gemstone.

IR = Irradiation

Enhancement of colour via the use of neutrons, gamma, ultraviolet, and/or electron bombardment.

TPL = Triplet

To add a clear protective layer on top of a Doublet. The top layer may consist of clear quartz, glass or hard plastic material. This is used to thicken and give additional strength to the item.

C = Coating

Enhancement by the application of an artificial layer to the surface.

B = Bleaching

Enhancement by heat, light, and/or chemical agents to lighten or remove colour.

O = Oiling

Enhancement by bathing the gemstone in an oil to enhance the lustre and clarity of a gemstone.

R = Reconstruction

Enhancement by use of heat, pressure, and/or solvents to fuse small pieces of a gem together into a larger whole. Often used in conjunction with a dye.

I = Impregnation

Enhancement by melted wax or plastic forming a layer over the surface of a gemstone to improve amongst other things lustre.

A = Assembled

Enhancement by assembling other substances over or under a gemstone to improve durability and size.

S = Smoking

Enhancement by smoking a gemstone and replacing its water content with carbon. Sometimes the smoke can be dyed.

DBL = Doublet

A thin layer of natural stone adhered to a backing material. The doublet backing material is used to thicken and give strength to the item.

HTLE = Heat and Light Elements

Enhancement by adding a chemical element during the heating process of a gemstone.

Gemstone Enhancement Prevelance Purpose Durability / Stability Detection Care & Cleaning
Abalone No Enchancement (N)         No specific care required, see above for more detailed information on jewellery care
Agate No Enhancement (N) e.g, dendritic agate          
Dyeing (D) e.g, pink agate Common To enhance or introduce colour Good Detectable by a qualified Gemmologist without use of sophisticated equipment No specific care required, see above for more detailed information on jewellery care
Alexandrite No Enhancement (N)          
Amber Heating Common To enchance colour and creat sun spangles Good Detectable by a qualified Gemmologist without use of sophisticated equipment No specific care required, see above for more detailed information on jewellery care
Amethyst No Enhancement (N) e.g, many of our Zambian, Kalomo and African Amethyst are untreated Occasionally        
Heated (H) e.g, most of our Brazilian amethyst is heated Common To enhance colour Excellent Not detectable No specific care required, see above for more detailed information on jewellery care
Ametrine No Enhancement (N)       Not detectable No specific care required, see above for more detailed information on jewellery care
Ammolite Assembled (A) Routien To protect the thin layer of ammolite Excellent Detectable by a qualified Gemmologist without using sophisticated equipment No specific care required, see above for more detailed information on jewellery care
Andesine Diffused (U) Common To produce colour Good Detectable by a qualified Gemmologist using sophisticated equipment No specific care required, see above for more detailed information on jewellery care
Apatite No Enhancement (N) e.g, all our green apatites         As apatite has a low hardress rating be careful when wearing the stone
Heated (H) e.g, blue apatites Routine To enhance colour Good Detectable only with an internationally accredited laboratory As apatite has a low hardress rating be careful when wearing the stone
Aquamarine Heated (H) Routine To remove yellow and green overtones, resulting in more a pure blue colour Very good Not detectable No specific care required, see above for more detailed information on jewellery care
Chalcedony Dyeing(D) Common To produce a variety of different colours Good Detectable by a qualified Gemmologist without using sophisticated equipment - often assumed dyed due to unnatural colour No specific care required, see above for more detailed information on jewellery care
Charoite No Enhancement (N)          
Impregnation (I) Common To improve lustre Good Detectable by a qualified Gemmologist using sophisticated equipment No specific care required, see above for more detailed information on jewellery care
Citrine No Enhancement (N), e.g, Madeira Citrine Only Madeira cirtine is untreated        
Heated (H) Routine To turn amethyst into Citrine Excellent Not detectable No specific care required, see above for more detailed information on jewellery care
Danburite No Enhancement (N)          
Diamonds (White) No Enhancement (N) Routine       No specific care required, see above for more detailed information on jewellery care
Diamonds (Cognac, Brown or Champagne) No Enhancement (N) Routine       No specific care required, see above for more detailed information on jewellery care
Heated (H) Occasionally To enhance colour Excellent Detectable only with an internationally accredited laboratory No specific care required, see above for more detailed information on jewellery care
Diamonds (Red, Black, Green, Yellow, Blue) Irradiated (IR) Routine To enhance colour Very good Detectable only with an internationally accredited laboratory No specific care required, see above for more detailed information on jewellery care
Diaspore No Enhancement (N)         No specific care required, see above for more detailed information on jewellery care
Diopside No Enhancement (N) including star diopside         No specific care required, see above for more detailed information on jewellery care
Emerald No Enhancement (N) Rare        
Oiled (O) e.g, our Zambian emerald is normally oiled Routine To enhance the clarity and lustre Fair Detectable by a qualified Gemmologist without using sophisticated equipment Can easily be reoiled by customer. Avoid ultrasonic cleaners
Filling (F) e.g, our Columbian emerald is normally filled Common to enhance clarity and lustre Fair Detectable by a qualified Gemmologist without using sophisticated equipment May need professionally re-treating every so often. Avoid ultrasonic cleaners
Fluorite No Enhancement (N), e.g, our multi coloured fluorites in strands         As fluorite is low on the hardness scale, handle with care
Irradiation (IR) Common To improve colour Good Detectable only with an internationally accredited laboratory As fluorite is low on the hardness scale, handle with care
Garnet No Enhancement (N) e.g, all garnets exepct demantoid         No specific care required, see above for more detailed information on jewellery care
Heating (H) only demantoid and is only very low heat Rarely To enhance colour Excellent Detectable only with an interntionally accredited laboratory No specific care required, see above for more detailed information on jewellery care
Goshenite No Enhancement (N)         No specific care required, see above for more detailed information on jewellery care
Heliodor Irradiated (IR) Common To alter colour Good Detectable only with an internationally accredited laboratory No specific care required, see above for more detailed information on jewellery care
Howlite Dyeing(D) Occasionally To alter colour Good Detectable by a qualified Gemmologist without using sophisticated equipment No specific care required, see above for more detailed information on jewellery care
Impregnated (I) Common To improve lustre Good Detectable by a qualified Gemmologist using sophisticated equipment No specific care required, see above for more detailed information on jewellery care
Iolite No Enhancement (N)         No specific care required, see above for more detailed information on jewellery care
Kunzite irradiation (IR) Routine To enhance colour Fair Detectable only with an internationally accrediated labratory Avoid exposure to p light and high heat
Kyanite No Enhancement (N)         No specific care required, see above for more detailed information on jewellery care
Labradorite No Enhancement (N)         No specific care required, see above for more detailed information on jewellery care
Lapis Lazuli Dyeing (D) Common To improve colour and remove white calcite inclusions Very Good Detectable by a qualified Gemmologist without using sophisticated equipment No specific care required, see above for more detailed information on jewellery care
Malachite Impregnated (I) Common To improve lustre Very Good Detectable by a qualified Gemmologist without using sophisticated equipment No specific care required, see above for more detailed information on jewellery care
Moldavite No Enhancement (N)         No specific care required, see above for more detailed information on jewellery care
Moonstone No Enhancement (N)         No specific care required, see above for more detailed information on jewellery care
Morganite Heating (H) Common To drive out orange colours, and produce a purer pink colour Very good Detectable only with an internationally accrediated laboratory Avoid extreme temperature and sudden temperature change
Mother of Pearl Dyeing (D) Common To alter colour Good Detectable by a qualified Gemmologist using sophisticated equipment No specific care required, see above for more detailed information on jewellery care
Bleaching (B) Rare To remove colour Good Detectable by a qualified Gemmologist using sophisticated equipment No specific care required, see above for more detailed information on jewellery care
Opal No Enhancement (N) e.g, Welo opal and Australian opal Common       Avoid heat as it can evaporate opal's water content resulting in crazing
Smoking e.g, black opals Rare, only black opals To create dark background colour and enhance play of colour Fair Detectable by a qualified Gemmologist using sophisticated equipment Avoid heat as it can evaporate opal's water content resulting in crazing
Paua Shell No Enhancement (N)         No specific care required, see above for more detailed information on jewellery care
Cultured Pearl Bleaching (B), e.g, white pearls Routine To remove colour and produce a purer white colour Very good Not detectable but assumed treatment has taken place  
Dyeing(D), e.g, any other colour than white Common To produce colours Very good Detectable by a qualified Gemmologist using sophisticated equipment  
Peridot No Enhancement (N)         No specific care required, see above for more detailed information on jewellery care
Petalite No Enhancement (N)         No specific care required, see above for more detailed information on jewellery care
Quartz No Enhancement (N) e.g, white quartz and rutile quartz Common       No specific care required, see above for more detailed information on jewellery care
Coating (C) e.g, mystic quartz Occasionally To produce colour Fair Detectable by a qualified Gemmologist without using sophisticated equipment Avoid scratching the pavilion as the coating can scratch
Irradiated (IR) e.g, smokey quartz and blueberry quartz Occassionally To enhance colour Good Not detectable No specific care required, see above for more detailed information on jewellery care
Dyeing(D) e.g, blue quartz Rare To produce colour, must be quench crackled first to produce fractures Good Detectable by a qualified Gemmologist without using sophisticated equipment No specific care required, see above for more detailed information on jewellery care
Heated (H) Common To enhance colour Very Good Not detectable No specific care required, see above for more detailed information on jewellery care
Rhodocrosite No Enhancement (N)         No specific care required, see above for more detailed information on jewellery care
Ruby No Enhancement (N)         No specific care required, see above for more detailed information on jewellery care
Heated (H) Routine To enhance colour Very Good Detectable by a qualified Gemmologist without using sophisticated equipment No specific care required, see above for more detailed information on jewellery care
Diffused (U) Common To enhance colour Good Detectable by a qualified Gemmologist using sophisticated equipment No specific care required, see above for more detailed information on jewellery care
Filled (F) Common To improve clarity and colour Good Detectable by a qualified Gemmologist using sophisticated equipment No specific care required, see above for more detailed information on jewellery care
Sapphire No Enhancement (N) Rare       No specific care required, see above for more detailed information on jewellery care
Heated (H) Routine To enhance colour Very Good Detectable by a qualified Gemmologist using sophisticated equipment No specific care required, see above for more detailed information on jewellery care
Diffused (U) Common To enhance colour with beryllium Good Detectable by a qualified Gemmologist using sophisticated equipment No specific care required, see above for more detailed information on jewellery care
Filled (F) Rare To improve colour and clarity Good Detectable by a qualified Gemmologist using sophisticated equipment No specific care required, see above for more detailed information on jewellery care
Dyeing(D) Rare To enhance colour Fair Detectable by a qualified Gemmologist using sophisticated equipment No specific care required, see above for more detailed information on jewellery care
Scapolite No Enhancement (N)         No specific care required, see above for more detailed information on jewellery care
Sillimanite No Enhancement (N)         No specific care required, see above for more detailed information on jewellery care
Snowflake Obsidian No Enhancement (N)         No specific care required, see above for more detailed information on jewellery care
Sodalite No Enhancement (N) Common       No specific care required, see above for more detailed information on jewellery care
Dyeing(D) Occasionally To enhance colour Very Good Detectable by a qualified Gemmologist using sophisticated equipment Avoid ultrasonic cleaners and steam cleaners as dye fades.
Sphene No Enhancement (N)          
Heated (H) Rare To create a red or orange colour Good Detectable by a qualified Gemmology using sophisticated equipment No specific care required, see above for more detailed information on jewellery care
Spinel No Enhancement (N)          
Heated (H) Rare To improve colour and clarity Excellent Detectable only with an internationally accredited laboratory No specific care required, see above for more detailed information on jewellery care
Sunstone No Enhancement (N)         No specific care required, see above for more detailed information on jewellery care
Tanzanite Heated (H) Routine To enchance colour Excellent Not detectable but assumed due to prevalance No specific care required, see above for more detailed information on jewellery care
Topaz No Enhancement (N) e.g, imperial topaz and white topaz Occasionally       No specific care required, see above for more detailed information on jewellery care
Heated (H) Rare To enhance colour Excellent Not detectable No specific care required, see above for more detailed information on jewellery care
irradiated (IR) e.g, blue topaz Common To enhance colour Excellent Detectable only with an internationally accredited laboratory No specific care required, see above for more detailed information on jewellery care
Coating (C) e.g, mystic topaz Common To produce colour in colourless topaz Fair Detectable by a qualified Gemmologist without using sophisticated equipment Avoid scratching as may remove the coating
Common To produce colour in colourless topaz Very good Detectable only with an internationally accredited laboratory No specific care required, see above for more detailed information on jewellery care
Tourmaline No Enhancement (N) e.g, chrome tourmaline         No specific care required, see above for more detailed information on jewellery care
Heated (H) e.g, green tourmaline Common To enhance colour Very good Not Detectable No specific care required, see above for more detailed information on jewellery care
Irradiated (IR) e.g, red, pink, purple tourmaline Occasionally To enhance colour   Not Detectable No specific care required, see above for more detailed information on jewellery care
Turquoise Impregnated (I) Common To enhance lustre Good Detectable by a qualified GEmmologist without using sophisticated equipment No specific care required, see above for more detailed information on jewellery care
Reconstructed (R) Occasional To produce stones that are available to set into jewellery Very Good Detectable by a qualified GEmmologist without using sophisticated equipment No specific care required, see above for more detailed information on jewellery care
Dyeing(D) Occasional To produce different colours than the natural blue Good Detectable by a qualified GEmmologist without using sophisticated equipment No specific care required, see above for more detailed information on jewellery care
Zircon No Enhancement (N) e.g, green and brown zircons         No specific care required, see above for more detailed information on jewellery care
Heated (H) e.g, red, blue and colourless zircons Routine To produce and enhance colours Very Good Not detectable but assumed due to prevalance No specific care required, see above for more detailed information on jewellery care