I have collected this information for many years. I believe most is correct. Do research for more information.

AGATE – Many are dyed or heated to add or alter the natural color.

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AMETHYST – Heating is applied on occasion to lighten color or to remove a smoky appearance. Darker shades are rarely heated unless extremely dark. This treatment is considered permanent and should last a lifetime. Some, from one mine, when heated turns a light green. JAPANESE AMETHYST – This material is ground up amethyst that has been regrown under heat and pressure. It is 100% amethyst and is called Reconstructed by GIA. I have been told they do this with Citrine also. However, I have not found anything to confirm this yet. I have also been told these crystals -grown in Japan – are mixed in with mine run rough before it is sent to the cutter. So, it is possible all of you reading this may have bought some of this material. Is is all amethyst. Just regrown crystals under perfect conditions.

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AQUAMARINE – Sometimes it is heated to remove yellow for a more blue color. It may make the color more uniform so little yellow or green shows. Also heated to bring out a stronger blue color.

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CITRINE – Usually heated to enhance or give golden or yellow colors a better look. Brownish varieties of amethyst are commonly heated and they turn into yellow or orange colors and are then called Citrine.

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EMERALD – Colorless oils, colored oils and various polymers are used to improve appearance. Sometimes hardeners are used along with color to try to make the process more permanent. If the process starts to deteriorate, it is nearly impossible to make the emerald look good again. Oiling seems to be the best and most accepted process of treatment from what I have read. Reoiling is simple. Proper care makes this process fairly permanent.

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JADE, LAVENDER – Sometimes dyed to alter the color of the stone.

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KUNZITE – Heated to enhance color. Kunzite is a light sensitive stone. Color can fade as light shows on it over a period of time. This may even happen to gems that have not been heated.

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MORGANITE – Sometimes Cobalt heated to produce a green color.

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OPAL (DOUBLET) – This is an assembled stone. Many times both parts are natural opal. Black onyx, basinite and other materials are sometimes used as a backing. The top is opal. The bottom may or may not be. This process makes the final piece stronger and brighter as the light entering is bounced back from the dark backing.

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OPAL (TRIPLET) – Similar process to the doublet except the top is usually covered with a slightly domed cabochon of quartz. This protects the opal and magnifies the fire from the opal.

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QUARTZ – Some are treated to enhance color. Some receive a low level radiation treatment to receive a lovely color. Many of the yellow are done this way. A low level treatment is used and is of no risk.

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BI-COLOR QUARTZ – Purple/White, Golden/White, Yellow/Green, Orange/Blue and other combinations including some ametrine. Assume these have been lab created, heated or treated in some other way. Not much information seems to be available on these. I will post it as I find it.

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RUBY – Heated to enhance color. Beryllium treated for brighter stone and fills inclusions. Fissure filled (lead glass filled) is a new process of filling fissures to give the stone a better look. Many rubies are heavily treated using a high refractive index lead-glass to fill fractures and cavities, vastly improving the apparent clarity and potentially adding weight. The glass may be damaged by a variety of solvents. Stability is good to fair. Much is treated from lower quality ruby rough, commonly from Madagascar. The treatment seems not to be affected from heat until you go over 650 or 700 degrees. These are the most common treatments.

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SAPPHIRE – Commonly heated to enhance or change the color. Very common and helps to give uniformity to the color in many cases. Some purple or violet are heated to turn them into a lovely pink. A diffusion treatment is also done to give blue sapphires a better look. The color penetrates only the surface to about .2 mm. Deep diffusion which takes more time may penetrate to .4 mm. Heating to a diffused sapphire usually creates a white coating on the stone and pretty much ruins it. Beryllium treatment (BE Heating) is commonly used today to give  corundum a  beautiful range of color. This treatment may send the color through the entire gem. It is a permanent process and can withstand heating without and white coating as there is no beryllium in corundum to begin with.

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SAPPHIRE (STAR) – Many are treated with a diffusion process giving the surface layer a coloring that enhances the star. The treatment penetrates about .2 mm deep. Many of the black or gray are diffused treated to blue for beautiful stones.

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TANZANITE – Heated to bring out the lovely lavender to purple colors. There is a limited amount natural unheated with good color. Most are heated. Slow heating is best. Fast heating can make the stone brittle.

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TOPAZ – Most blue colors are irradiated (cobalt) through various processes and steps to bring out the various colors. There are some natural blue. It usually is a lighter blue color and usually costs more.

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TOPAZ – There are many sellers on eBay and the Net selling something they are calling PINK TOPAZ and RED TOPAZ. I bought a couple to see what it was. It checked out as Pink topaz color LAB CORUNDUM. Beautiful material. They just do not tell you what it really is. Any I have is described as I know it to be.

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TOURMALINE – Heating is sometimes used to enhance the blue/green colors. The pink and salmon colors are sometimes irradiated to make it a stronger pink. Both processes are permanent

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ZIRCON – Heated to bring out a stronger blue color. They will also treat the white on occasion to make it brighter. Most material from Tanzania is natural color. It is usually clear to a root beer color.

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There certainly are many more that are not listed here. I try to add them whenever I hear about them.

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Other terms you should know. Most from AGTA – American Gem Trade Association which is a very good organization.

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ASSEMBLED ASBL – Assembled items are made of multiple layers of materials or combinations of manufactured and/or natural materials. Examples: Opal triplets and mosaics.

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BLEACHED B – Bleaching is the use of chemical agents to lighten or to remove a gemstone’s color. Be ware: Many pearls and Mother of pearl, if placed in the sun for extended periods of time, cause lightening to their color. This non-chemical form of bleaching still affects the durability of a pearl’s nacre. Bleaching is a permanent process.

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COATING C – Coating is a surface enhancement applied to improve a gem’s appearance, provide color, or contribute other special effects.

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DYED D – Dyeing is the application of coloring matter into a gemstones to give it a new color, intensify its present color, or improve its color uniformity. Dyes and natural gemstone colors may both be adversely affected by prolonged exposure to sunlight or fluorescent light.

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Enhanced E – The “enhancement” code indicates that type of gemstone is enhanced. Many enhancements are difficult or impractical to prove. A supplier may simply assume such enhancement has been done to a particular gemstones material being described. If the specific type of enhancement is known, its enhancement symbol will  be stated.

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Filled F – Filled gems are characterized by the presence of solidified borax or other colorless substance produced as a by-product of heat enhancement. The results are visible under properly illuminated 10x magnification.

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Gamma or Electron Irradiated G Gamma and/or electron bombardment may be used to alter a gemstone’s color. Gamma or electron irradiation may be followed by a heating process.

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Heated H – Heat may be used to alter color, clarity and/or other gem aspects. This is a gemstone treatment that has been used for centuries, possibly dating back to the Roman Empire. The results of heating are permanent under normal conditions. Heating is usually not detectable. Unheated rubies and sapphires may contain microscopic rutile needles or gas bubbles in pockets of liquid that can be used to determine that these stones have not been heated. If these gems are the finest color, they will command premium prices. Unless explicitly stated otherwise, assume the following gems are heated: rubies, sapphire, tanzanite, citrine, pink topaz, aquamarine, blue zircon and colorless zircon.

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Infilling I – Infilling is the intentional filling of cavities or fractures with glass, plastic, Opticon with hardeners, and/or hardened foreign substances. Infilling is performed to improve durability and/or add weight.

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Imitation IMIT – Imitation gems are man-made products, fabricated using materials such as glass, ceramics and/or plastics. Imitation gems resemble the appearance of a natural gemstone, but not duplicate its characteristic properties.

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Lasering L – Lasering is the use of laser’s and chemicals to reach and alter inclusions in gemstones, most notable diamonds. Lasering results in a visible trail that can be detected by a trained professional.

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Natural N – Natural stones are gems which are not known to be enhanced.

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Oiled or Resin Infused O – Oiling or resin infusion is the intentional filling of surface-breaking cavities of a colorless oil, wax, natural resin, or unhardened man-made material into fissured transparent/translucent gemstones. Oiling is performed to improve a gem’s appearance (e.g., as for emeralds). Although unoiled emeralds can be found, they are unusual and neither more nor less valuable than oiled gems. When rough emerald is mined it is often placed in oil. When emeralds are cut, oil is used as a lubricant.

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Irradiated R – Irradiation refers to the use of neutrons with the combination of any other bombardment.

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Stabilized or Bonded S – Bonding or stabilization is use of a colorless bonding agent, such as plastic, with a porous gemstone. The procedure is intended to enhance durability and/or appearance.

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Synthetic SYN – Synthetic gems are man-made materials which have essentially the same optical, physical and chemical properties as the natural counterpart.

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Diffusion U – Diffusion is the use of chemicals in conjunction with high temperatures to produce color and/or asterism (star-like inclusions). Diffusion is not a generally accepted gemstone treatment, since only a slight layer is actually treated. Therefore, if the surface is chipped or abraded, it cannot be repolished without removing the effect.

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Waxed or Oiled W – Waxing or oiling is the impregnation of a colorless wax, paraffin and/or oil in porous opaque gemstones to improve their appearance.

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Mystic Quartz, Topaz and CZ. These stones are treated through a heat process with a misting of specially mixed chemicals that put a coating on the stone. This coating is a patented process. It is more involved. I have simplified it here.

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IN SHORT, PLEASE TAKE CARE OF ANY GEMSTONES YOU BUY IF YOU WNT THEM TO LAST. YOU WOULD NOT BUY A NEW CADILLAC AND DRIVE IT IN A BAJA RACE WOULD YOU? TREAT YOUR GEMS ACCORDINGLY.

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THE DATA ABOVE HAS BEEN COMPILED FROM MANY SOURCES. I OFFER IT TO YOU AS A GUIDELINE ONLY. SOME INFORMATION MAY NOT BE EXACT. MOST SEEMS TO BE ACCURATE FROM WHAT I HAVE READ. IF YOU DO NOT WISH TO CONSULT THE ABOVE LIST FROM TIME TO TIME, ASSUME ANY ITEM MAY HAVE OR HAS TREATMENTS ACCORDING TO INDUSTRY NORMS.

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I try to disclose everything I know and list data above to help you. I do not do certificates of authenticity or appraisals. How could I provide one on a $10.00 stone? I cannot. There are so many treatments to gemstones today that I offer everything with this comment: If you are not comfortable with the information I have provided or my descriptions, please do not buy from me. I hope you will though. Example: If you shop eBay or the net, select any seller. Even if they say, as an example, they cut all of their amethyst from their own rough, that material came from a mine at one time. Much of the reconstructed rough may have been mixed in with the natural before it went to the cutter. The amethyst will test out anywhere as genuine – even if regrown in a lab. I have sold for more than 20 years and my customers really like my gems. Supply from around the world has changed so much in the last few years. The value of the dollar as well as certain economies strengthening affects what we must pay to purchase stones. I wish it were easy. It is not. But, we try very hard to find things and offer them at a good price to you. Regards, Rich and Debbie Day

Day Enterprises

PO Box 911, Roscoe, IL. 61073

(630) 258-9095

Copyright © 2018 Day Enterprises – All Rights Reserved.


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TREATMENTS extra

As we find more data or additional information on new stones, we will try to add to the list above.