What are the heat treatment processes used on sapphires?
Heating is an accepted treatment for sapphire. But for fine-quality sapphire, confirmation from an independent laboratory like GIA that there is no evidence of heat adds to a sapphire’s rarity and value. contact us Toll Free 800-421-7250 Outside U.S. & Canada 760-603-4000 Contact Us
Does heating a sapphire increase its value?
Heat enhancement is applied to sapphires or rubies is to improve colour and/or clarity. How to identify heat treatments? The most common changes Loosened rutile needles identify this sapphire as heat-treated These mineral inclusions are fused during heat treatment Often melted mineral inclusions resemble "snowballs" Stained colour zonings indicate
Is the color of a heated sapphire permanent?
Heat treatment is used to improve a sapphire’s color, remove color zoning, and improve clarity. Some heat treatment procedures are relatively mild, involving temperatures of about 400 degrees Celsius for brief periods of time.
Can a heated sapphire be used for jewelry?
HEAT TREATMENT OF SAPPHIRE. ( A layman's simplified explanation of the various levels of treatment) Sapphire is formed deep down below the earth's surface, some 65 kilometres down, and comes to the surface in a volcanic explosion in a 'formation tube' or vent. The sapphire comes up at the forefront of a volcanic eruption and is expelled with the pyroclast, or volcanic …
Are heat treated sapphires valuable?
Heating is an accepted treatment for sapphire. But for fine-quality sapphire, confirmation from an independent laboratory like GIA that there is no evidence of heat adds to a sapphire's rarity and value.
What does heat treating a sapphire do?
Heat Treating sapphires is a standard industry practice that improves the clarity and enhances the color of sapphires from Gem Mountain. Most people prefer the darker color saturation and improved clarity and brilliance of a heat treated stone over the pale pastel color of the average rough sapphire.
Are heat treated gems less valuable?
We attempt to let you know when a gem is treated. Heat treatment is the most common treatment and without heat treatment the availability of fine gems would be significantly less. With less gems prices would be dramatically higher only available to the rich.
Do heat treated sapphires fade?
The color of a heat-treated sapphire will remain permanent and will not change or fade, unless the stone undergoes a secondary treatment. This is the reason why heat treatment on sapphires is accepted by most retailers.
How can you tell if a sapphire is heat treated?
The results can be dramatic, transforming pale stones into ones with lively, saturated colors. Knowledgeable gemologists will be able to discern whether a sapphire has been subjected to this kind of extreme heating. When corundum is heated to between 1200-1600 degrees Celsius, star sapphires can be created or improved.
What is the rarest color of sapphire?
Insider View from the President of The Natural Sapphire Company: For padparadscha sapphires, it's a tough situation because there are so few natural stones available. This ultra rare mix of orange and pink is without a doubt the rarest color in a sapphire.
Is heated or unheated sapphire better?
By appearance, is there a difference between natural and heat-treated sapphires? Yes, but to a trained eye. Generally speaking, natural no-heat sapphires will have a softer luster and smoother surface appeal. Heated sapphires display a glass-like surface that feels hard and unnatural.Jul 13, 2021
When did heat treatment of sapphires start?
The first stones heated allegedly originated from the Pailin mines in Cambodia. Treated sapphire rough was given for cutting to lapidaries in the Jura Mountains of Europe at least by 1920 (and possibly as early as 1915).
What percentage of sapphires are heat treated?
95 percentIf a gemstone has been heat treated, it simply means it has undergone some type of thermal process in order to alter or improve its appearance. In this modern era, nearly 95 percent of sapphire gemstones are heat-treated for several important reasons.Jun 6, 2015
What does heat treatment do to gemstones?
What Is Heat Treatment? 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
How can you tell the quality of a sapphire?
You want to look for a sapphire that has no inclusions visible to the naked eye. experts look at the size, location and number of inclusions to judge clarity. The less visible the inclusions are, the higher the grade. Cut: The cut is essentially what makes a sapphire really sparkle.Mar 9, 2020
What is heat enhancement on sapphires?
Technical aspects of heat treatment to sapphires and rubies. “Heat enhancement is applied to sapphires or rubies is to improve colour and/or clarity.”. How to identify heat treatments? The most common changes.
How hot is a sapphire?
In this treatment, rubies and sapphires are usually heated above 1200°C.
What is thermal treatment?
The thermal treatment (burning / heating) of rubies and sapphires is a standard treatment in today’s market. What most people are unaware about is that the heating process helps optimize colour and clarity of gemstones. Here is a visual example of what effects heat treatment can have.
What is the FTC for gemstones?
The U.S. Federal Trade Commission (FTC), the International Coloured Gemstone Association (ICA) and the World Jewellery Confederation (CIBJO) have issued strict procedures that disclose the synthetic gemstone’s origin throughout the distribution channel at the time of sale, from the manufacturer to the consumer.
Can blue sapphires melt?
With heated blue sapphires, the colour zoning often follows former rutile needles. Heat treatment can often cause burst cracks to form around inclusions. Burst cracks often resemble "island atolls" in their structure. During the temperature treatment, even the surface of an already cut stone can melt.
Is sapphire natural or untreated?
However, “natural” does not mean the sapphire has not undergone any alterations. The key term is “untreated,” meaning a sapphire is natural (not lab created) and has not been subject to any chemical or heat treatments.
What is heat treatment on sapphires?
Heat treatment is used to improve a sapphire’s color, remove color zoning , and improve clarity.
Why is it important to treat sapphires?
Throughout history, it has been a common practice to treat sapphires in some way to enhance their color and clarity. It is important to understand the ways in which sapphires may be treated so you can make an informed decision. This is especially important with the modern technology that is abundant in 2020.
What is a melted padparadscha sapphire?
A Beryllium treated padparadscha sapphire showing a melted crystal, a telltale sign of treatment. During the 1990s, the treatment was hard to detect, since the coloring agent penetrated deeply and uniformly into the stone. As a result, many of these treated sapphires were mistaken for natural padparadschas.
What is sandpaper sapphire?
Here is “sandpaper quality” sapphire that is treated to produce commercially valuable stones. Unlimited quantities of “sandpaper quality” sapphire exist that can be used for treating. These stones are then cut and put into jewelry for sale.
What color is a sapphire?
Pale yellow, faint brown, and grayish sapphires are sometimes exposed to controlled radiation in order to induce an attractive, saturated golden yellow to orange-yellow color. While these stones are safe to wear, their color is not usually stable and will fade quickly under bright light or if heat is applied.
What temperature should I use for pink sapphires?
Some heat treatment procedures are relatively mild, involving temperatures of about 400 degrees Celsius for brief periods of time. These are commonly used on pink sapphires from the mines of Madagascar and may also be applied to Madagascar’s coveted padparadscha sapphires. An unheated ruby with natural inclusions.
What element is used to make sapphires?
Newer diffusion techniques use the element beryllium, which has a smaller atomic structure than titanium, so it is capable of penetrating deeper into the sapphire. While titanium colors pale sapphires blue, beryllium is most often used to induce orange or golden hues.
What is the chemical diffusion process of sapphires?
The chemical diffusion process is carried out by multiple heat treatments of the sapphire in the presence of artificially introduced elements like beryllium or titanium, which penetrate the structure of the sapphire. The beryllium treatment is carried out to produce golden, yellow, orange, apricot, padparadschas and similar colours ...
What is the name of the ash that is expelled from a sapphire?
The sapphire comes up at the forefront of a volcanic eruption and is expelled with the pyroclast, or volcanic ash. This is typical for all Australian sapphire occurrences. If the temperature in this formation tube is hot enough, and the residence time is long enough, the sapphire is clarified, on its journey to the surface.
Why are sapphires left with veils?
However, if the temperature is too low, or the rate of travel of the sapphire and pyroclast up the tube too rapid, the sapphire may be left with inclusions such as the "silk" veils which often cloud natural sapphire crystals.
How many times is geuda stone heated?
The geuda stone is heat treated as many as six or eight times in order to clarify it and produce the pale "Ceylon Blue" which is sold at quite high prices - but is essentially a heat generated colour. d. Bulk Chemical Diffusion - Beryllium Treatment.
Where does Ceylon sapphire come from?
Much of the "Ceylon" sapphire on the market comes from Australia or from Madagascar and may have been subject to a simple treatment process, but a portion of it started off life as Geuda Stone from Sri Lanka. This very highly included stone looks like a "moldy potato" before heat treatment.
Do you have to disclose beryllium sapphires?
Persons selling beryllium treated sapphires are required to disclose the fact clearly and adequately to purchasers. However, since some sellers have been known not to make the requited disclosure, buyers are recommended to seek a guarantee or statement of authenticity for their purchases.
Is heat treatment good for sapphires?
Simple Heat Treatment. This is considered quite acceptable in the jewellery trade as no chemicals are added and the sapphire is not changed chemically apart from the removal or conversion of the rutile and contaminant bonds.
Why do we heat treat sapphires?
It can also be used to improve the clarity of a particular sapphire by removing, or at the very least reducing, inclusions.
How does heat treatment affect gemstones?
For countless centuries, the human race has utilized heat treatment to improve the quality and appearance of gemstones. Although the techniques used in the past were generally unreliable and may not have always resulted in a good result, the past 100 years has seen a rapid growth in the development of these important techniques, and today they are entirely reliable and guarantee a fantastic visual result. Heating can lighten, darken, deepen or completely change a gemstone’s color. Treatments can vary from simple, like holding the gem over an open flame, to complicated processes involving furnaces controlled by computers.
Why heat sapphires?
Why heat sapphires? To improve the color, offer various sizes, get a higher return on investment, and offer customers an affordable choice. An individual or company in the early stages of the supply chain felt that their unearthed, pre-heated stone lacked a desirable color. They can choose to leave the stone as-is or mark it for heat treatment. If they were to leave the stone in its natural state they would not reap a financial gain. But if they improve the color via heat treatment, the stone becomes more sellable and they can get a better return on their investment. For the consumer, these stones are a great, lower-cost, alternative to natural, un-heated sapphires.
What is sapphire mineral?
GEMOLOGY 101: SAPPHIRE. Sapphires are a variety of the mineral Corundum, which is chemically Aluminum Oxide. Other members of the corundum family include ruby, padparadscha (orangy-pink), pink sapphire, yellow sapphire, star sapphire, and many other hues of sapphires. But regardless of their color, the foundational composition for all these ...
Why are sapphires blue?
The blue color in sapphires is attributed to the type and amount of Titanium and Iron present in the crystal. The right balance of Titanium, Iron, with Aluminum Oxide will result in a beautiful blue color sapphire.
What is the best color for sapphires?
Unheated Sapphires. Sapphires with a vivid/royal blue color and fine clarity, which have not undergone any treatment, are the ideal investment. They are becoming increasingly rarer and demand remains high. Additionally, many signed, vintage, and antique pieces by famous houses are set with natural, unheated sapphires.
Is sapphire a good alternative to unheated sapphires?
The treatment is effective , stable, and allows an affordable alternative to unheated natural sapphires. Although heated sapphires are available at every brick-and-mortar or online retailer, natural unheated sapphires are rarer, admired for their legends, and coveted for their appearance, use in iconic and uber-fine jewelry, and long-term value.
Is a sapphire a good niche?
Regardless, a fine-quality natural sapphire, whether unheated or heated, is a good niche.
Do sapphires have crystals?
No, the important factors for a desirable gem stone are a beautiful color, eye-clean clarity, well-cut, and pleasant crystal. However, heated sapphires do lack the natural and rarity appeal of unheated sapphires.
What is a sapphire treatment?
Sapphire Treatments. Sapphire Treatments refers to the process of improving the clarity, colour and value of Sapphires that have been mined out of the ground. There are many types of Sapphire Treatments that are common practice in the market today and this article will outline them.
What is a low quality sapphire?
A low quality Sapphire that contains surface reaching fissures or cracks is filled with a cobalt rich form of glass. The Cobalt turns the Sapphire blue while the glass fills the cavities and improves the clarity. This treatment must be disclosed clearly on all Sapphires.
What is the process of chemical diffusion of sapphires?
Beryllium Treatment. The chemical diffusion process is carried out by multiple heat treatments of the sapphire in the presence of artificially introduced elements like beryllium, which penetrate the structure of the Sapphire.
Can you heat treated sapphires?
In certain cases the amount of included material is too great to be removed by the simple one-off heat treatment process. So multiple heat treatments are done, sometimes in the presence of fluxing agents, which eventually lead to a clearer or brighter stone of an acceptable colour. This form of treatment is also accepted in the industry as simple heat treatment. View all Heated Sapphires.
