Why are gemstones heat treated?
Heat Treatment is a gemstone's exposure to high temperatures that alters the color and increases the clarity. Specifically, heating is used to lighten, darken or enrich the color. Without heat treated gemstones, fine gems' availability in the most desirable colors would be scarce.Mar 19, 2021
Are treated gemstones less valuable?
Treated gemstones are cheaper. This is one of the biggest advantages of a treated gemstone. Most people want to buy or wear an emerald but since an emerald costs $50K per carat (untreated), most people cannot afford it.May 24, 2019
What is gemstone coating?
A gemstone which is covered by an artificially applied transparent material or mineral to enhance its colour and appearance, is known as a coated gemstone. The technique is often used with coloured Topaz to create Mystic Topaz, and colourless Quartz is turned into Mystic Quartz using the same process.
What is gem enhancement?
Gemstone enhancements are applied to gems to improve their appearance and wearability. Some of these procedures have been used for centuries, while others are recent. People in the gem industry choose treatments based on the gem type and the desired effect.
How can you tell if a gemstone is dyed?
Another thing you can look is the colors of the gemstone. If you observed that there are areas of the gemstone where the color is extremely concentrated than the other areas of the stone, then it's likely dyed.Jun 30, 2015
What is a natural gemstone?
A natural gemstone is a mineral, stone, or organic matter that can be cut and polished or otherwise treated for use as jewelry or other ornament. A precious gemstone has beauty, durability, and rarity, whereas a semiprecious gemstone has only one or two of these qualities.Jun 18, 1997
Can gemstones fade?
Some gemstones are light-sensitive and fade when exposed to sunlight for long periods. Bright sunshine can also make them brittle and breakage-prone. Below are some of the most common gems susceptible to bright light. Amber can darken with age.Jul 15, 2020
What is diffusion treatment in gemstones?
Diffusion treatment consists of exposing the surface of a stone to certain chemicals combined with high heat in a furnace. Generally, only the surface color changes, so if you sliced the gem in half, the inside of the stone would be a different color, usually a paler, less valuable color.Sep 4, 2006
What is irradiated stone treatment?
The gemstone irradiation is a process in which a gemstone is artificially irradiated in order to enhance its optical properties. High levels of ionizing radiation can change the atomic structure of the gemstone's crystal lattice, which in turn alters the optical properties within it.
Why are gemstones treated?
Treatment refers to any process other than cutting and polishing that improves the appearance of the color or clarity, or that are used to alter the appearance (color, clarity or phenomena), durability, value, or supply of a gemstone. Today, most gems are treated to improve appearance.
Which gemstones are not treated?
Untreated Orange, Brown, and Rose Zircon Gemstones While the popular blue zircon is heat treated, there are natural zircon gems that are not treated in any way. These include brown, rose, rose-orange and golden orange zircon gemstones. Note that yellow and white zircon is almost always heat treated.
Which oil is good for gemstone?
Oiling gemstones to fill internal fractures is a common practice. Many different oils are used for emerald fractures. For example, using colorless cedarwood oil is a supposedly acceptable practice.
What is a gemstone treatment?
Treatment refers to any process other than cutting and polishing that improves the appearance of the color or clarity, or that are used to alter the appearance (color, clarity or phenomena), durability, value, or supply of a gemstone. Today, most gems are treated to improve appearance. Treatment processes can consist of heat, ...
What is the most common treatment for gems?
The heat treatment of gems is the most common treatment technique used on gems. Reference to heat treatment of gems is found in gemological literature dating back thousands of years. However, widespread use started in the 20 th century. This treatment is usually detectable in many gems.
What is dyeing gemstones?
Dyeing refers to one of the oldest treatments recorded. The treatment involves the introduction of a coloring agent into a gemstone to give it a new color, intensify an existing color or improve color uniformity.
What is the process of irradiating a gemstone?
Irradiation refers to the use of neutrons, gamma, and/or electron bombardment to alter a gemstone’s color. The irradiation stage of the process is then usually followed by a heating phase to effect the change. Blue topaz is typically produced by irradiation.
What is oiling a gem?
Oiling refers to a filling of surface reaching cracks or fissures in a gem with a colorless oil or resin, wax or other substance except glass or plastic, to improve the gemstone’s appearance. The purpose is to diminish the visibly of fractures and thus improve transparency in the stone. The treatment is usually not permanent.
What is clarity enhancement?
Clarity enhancement/Fracture filling refers to the filling of surface breaking fractures or fissures with colorless glass, resin or similar substance. This process is done to improve durability, color and transparency.
Is heat treatment permanent?
This treatment is usually detectable in many gems. Heat treated gems are stable and the treatment is usually permanent. The vast majority of gemstones are heated to alter their color. In ruby and sapphire the treatment is often performed to improve color and clarity.
Why do people use gemstone enhancements?
Gemstone enhancements are applied to gems to improve their appearance and wearability. Some of these procedures have been used for centuries, while others are recent. People in the gem industry choose treatments based on the gem type and the desired effect. Although some gemstone enhancements are commonplace, the gem-buying public remains ...
How does blue topaz get its color?
That doesn’t mean these gems are radioactive or otherwise harmful. Most blue topaz gems get their color in a two-step enhancement process. First, radiation modifies electron sharing between certain atoms in the crystal structure of colorless topaz, which turns the stone brown. Next, heating creates a stable blue color.
Is radiation a scary word?
Now you know why some in the gem industry are nervous about full disclosure. Radiation is a scary word. Revealing that a gem was irradiated will likely drive away customers. But just as with heating, radiation enhancements duplicate what happens in nature.
Do emeralds have internal fractures?
Some gems, notably emeralds, have internal fractures. Light reflection off their surfaces seriously affects the clarity and brilliance of these stones. Simply filling these fractures with a substance with similar optical properties makes these tiny cavities transparent.
Who is Donald Clark?
Donald Clark, CSM founded the International Gem Society in 1998. Donald started in the gem and jewelry industry in 1976. He received his formal gemology training from the Gemological Institute of America (GIA) and the American Society of Gemcutters (ASG). The letters "CSM" after his name stood for Certified Supreme Master Gemcutter, a designation of Wykoff's ASG which has often been referred to as the doctorate of gem cutting. The American Society of Gemcutters only had 54 people reach this level. Along with dozens of articles for leading trade magazines, Donald authored the book "Modern Faceting, the Easy Way."
What is the color of a gemstone?
The most extensively studied gemstone diffusion treatment involves the migration of the element beryllium into sapphire. The result creates a new color in the material, frequently orange but also blue, yellow, or red. In large stones, you can see the altered color zone as a surface layer through immersion in a refraction liquid. However, in small stones, the beryllium may penetrate through the entire body, so they have no visible color zones.
What is green amethyst?
Although amethyst may turn brownish or red at a temperature between 400 and 500° C, sometimes it turns a green color. While such heated gems are sometimes called “greened amethyst” or “green amethyst,” these are misnomers. Green quartz is properly known as prasiolite.
What color is coral?
(You can learn more about jade treatments here ). Dyes can give coral a more desirable (typically red) color. Black coral can be bleached to produce a “golden” material.
How is black onyx made?
“Black onyx” is made by soaking grayish colored chalcedony in a sugar solution and then blackening in sulfuric acid. This process leaves very tiny particles of carbon in the pore spaces of the chalcedony.
What color does tourmaline turn?
Heating usually lightens the color of tourmaline but can also sometimes turn a dark green stone an attractive, emerald-like color. Gamma irradiation of tourmaline produces spectacular color changes. Pale pink and some colorless stones may turn dark pink.
How rare is aquamarine?
Dark blue aquamarine is quite rare and very costly. Many of the dark stones seen in jewelry are produced by heating greenish or brownish material to a temperature of 400-450°C. The treatment results in a permanent color change.
What color is Tanzanite?
Heating certain crystals, which eliminates the red-violet color component, produces the lively sapphire-blue color that has made the gem so popular.
What does a gemstone treatment code mean?
Gemstone treatment codes indicate whether a gemstone has been treated or not. An untreated gemstone will not have enhancements. However, if you see that a gemstone has been treated, you will know to ask for more information about particular enhancements.
What is enhancement in gemstones?
Some enhancements can be merely cosmetic to improve clarity, color, or brilliance, while others stabilize the gem’s chemical composition. The term “treatment” is an indicator of whether a gemstone has been treated or not. Enhancements are the specific changes that have been applied to treated gemstones. Both gemstone treatments and gemstone ...
What is gamma treatment?
It is used only if a crack is visible at 10 times magnification. G (Gamma): Otherwise known as electron irradiation, gamma treatment changes a gemstone’s color. The irradiation process is sometimes followed by a heating process to stabilize color.
What is the rarest jade?
This type of jade is the rarest and valuable, requiring almost no treatment aside from waxing. TB (Type B Jade): Type B jade is a natural jade that is bleached in acid to remove undesirable staining, and then impregnated with wax or polymers.
What is the top layer of a stone?
The top layer may consist of clear quartz, glass, or hard plastic. This layer thickens and gives additional strength to the stone. W (Waxing/Oiling): The impregnation of colorless wax, oil, or paraffin into porous opaque gems to improve appearance. Filed Under:
What is a DBL?
DBL (Doublet): Jewelers make a doublet by gluing a thin layer of natural stone to a backing material. This treatment is used to thicken and give strength to the stone. D (Dyeing): Placing colored matter into a gem to give it a new color or greater intensity.
What is gemstone treatment?
It has been cut or polished to bring out its sparkle and color. When we talk about gemstone treatments, though, we refer to treatments which enhance color or clarity.
What is heat treated gemstone?
Heat treating is usually done to change or enhance color in a gemstone. Some gemstones are also “created” through this process. Citrine for example is generally heat-treated smoky quartz or amethyst. It has an entirely different color or appearance prior to being heat treated.
What does it mean when a gemstone is cut?
Any gemstone you purchase that isn’t in its raw state has in a sense been enhanced by a jeweler. It has been cut or polished to bring out its sparkle and color.
Is prasiolite a green amethyst?
Prasiolite is often found under the name “green amethyst”. This is wrong as amethyst is always violet or purple. Amber is commonly heat treated in order to darken the color and clarify the gem. Aquamarine is heat treated in order to remove a natural greenish tint which is common to the gem.
What is the process of bleaching a gemstone?
Bleaching is a process that removes color from a gemstone. It is usually done in combination with dyeing. Gemstones which are commonly bleached include jadeite jade (to remove unwanted brown coloration), pearls, coral, chalcedony, and tiger’s eye. Some of these are only bleached to lighten their color.
What gemstones are dyed?
Many types of gemstones are dyed, including pearls, quartz, lapis lazuli, turquoise, and more. Quite often when you see a bright, unexpected color in a gemstone, you should suspect dyeing. If you have ever been to a rock shop and looked at the tumbled gemstones, odds are you have encountered a lot of cheaply dyed gems.
What is the treatment for porous gemstones?
This is a treatment done to some porous gemstones. It involves the use of wax, plastic or polymer. The wax or other substance being used is poured over the stone to fill the porous spots and create a smoother texture and appearance. This can also make the gemstone more durable.
What is the treatment for turquoise?
Numerous treatments exist for turquoise. Some turquoise stones (as well as turquoise imitations) contain dye. Some are reconstituted from small pieces and dust, then mixed with polymer to bind them. Others receive polymer or epoxy coatings to improve their hardness.
What is reconstituted amber?
Reconstituted amber consists of several pieces pressed or melted together. In some cases, the people creating reconstituted pieces add modern insects to the mix. Artificial resins as well as copal may also be added to the mix. Reconstituted gems often exhibit a mosaic structure, which may only be visible under high magnification.
How to improve tiger eye color?
Tiger’s eye may receive treatment to improve its color. Heat treatment can help develop red colors. Bleach can lighten darker stones. In addition, dyes can enhance or alter the gem’s color.
Where does Addison spend her winters?
When she isn't writing about gems and minerals, Addison spends winters studying ancient climates in Iceland and summers hiking the Colorado Rockies.
What is the best way to polish pearls?
Most pearls also undergo maeshori heat treatment to enhance their luster and a gentle polishing to coat them with wax.
Is citrine a natural color?
Citrine. Since natural-color citrine is rare, most of the material on the market has under gone treatment. In fact, heating amethyst produces most citrine, in strong yellow or orangey hues, while heating smoky quartz can produce lemon-yellow hues. These treatments are undetectable.
What color is feldspar?
This treatment gives them an intense red color similar to some natural-color Oregon sunstones.
Coating
Dyeing
- Dyeing refers to one of the oldest treatments recorded. The treatment involves the introduction of a coloring agent into a gemstone to give it a new color, intensify an existing color or improve color uniformity.
Clarity Enhancement/Fracture Filling
- Clarity enhancement/Fracture filling refers to the filling of surface breaking fractures or fissures with colorless glass, resin or similar substance. This process is done to improve durability, color and transparency.
Heating
- The heat treatment of gems is the most common treatment technique used on gems. Reference to heat treatment of gems is found in gemological literature dating back thousands of years. However, widespread use started in the 20thcentury. This treatment is usually detectable in many gems. Heat treated gems are stable and the treatment is usually permanent. The vast majority o…
Flux Healing
- This treatment typically occurs in ruby and sapphire during the heat treatment with flux components melting into and solidifying on the surface reaching fractures of the stone. In many cases this would improve the clarity by “healing” the fractures.
Diffusion Treatment
- This treatment is achieved by heating sapphire extremely high temperatures while adding certain elements such as beryllium, chromium and/or titanium to the process. Currently detection of Be-diffusion is only possible using LA-ICP-MS and LIBS which are highly advanced and expensive spectroscopy techniques. On the contrary, Ti-diffusion treatment is generally detectable using m…
Irradiation
- Irradiation refers to the use of neutrons, gamma, and/or electron bombardment to alter a gemstone’s color. The irradiation stage of the process is then usually followed by a heating phase to effect the change. Blue topaz is typically produced by irradiation.
Oiling
- Oiling refers to a filling of surface reaching cracks or fissures in a gem with a colorless oil or resin, wax or other substance except glass or plastic, to improve the gemstone’s appearance. The purpose is to diminish the visibly of fractures and thus improve transparency in the stone. The treatment is usually not permanent.