DOES HEAT TREATED AMETHYST FADE IN SUN HOW TO
DOES HEAT TREATED AMETHYST FADE IN SUN CRACK

DOES HEAT TREATED AMETHYST FADE IN SUN CRACK

Like opals, pearls can dry and crack from excess heat produced by exposure to direct light.

Opals are generally stable, but the heat from intense light can create fractures, known as “crazing.”.Bright lights can cause kunzite to fade.The oils in emerald may dry or alter the stone’s appearance.When dyed, coral may fade under direct light.Below are some of the most common gems susceptible to bright light. Bright sunshine can also make them brittle and breakage-prone. Some gemstones are light-sensitive and fade when exposed to sunlight for long periods. Pale yellow sapphire can be heated to produce golden yellow sapphire.Kunzite is one of the most well-known stones susceptible to light. Sapphires with very small rutile inclusions (silk) can be heated to a high temperature and cooled quickly to produce a clearer stone. Heating some sapphires to a high temperature in an oxygen-free environment will deepen its blue color, while heating it in air can lighten it. Rubies with very small rutile inclusions (silk) can be heated to a high temperature and cooled quickly to produce a clearer stone. Heating ruby can take away the purple hue and produce a pure red color. Unless there is a lab report stating it’s not, you should assume heat treatment has been applied. The following gemstones are routinely heated. For example, a large high quality ruby with little to no inclusion is extremely rare, if it’s untreated, the price can be 3-5 times higher than the heated ones.įor cases like blue topaz and tanzanite, heating will increase the value of the gemstone as the original color is not desirable for most buyers.

The rarer the gemstone, the more premium can be charged for the unheated version. However, for high quality and higher priced gems, like ruby and sapphire, that are unheated and come with a lab report that states there is no evidence of heating, the price will be higher. For example, a carnelian that is heated for its fiery orange color won’t have a much higher price tag than an untreated one. So the lab couldn’t conclude whether the result is by nature or by heat that’s applied afterwards.įor lower-priced gemstones, the price between heated or unheated won’t differ too much generally. This is because the temperature of heat treatment is low and could have happened in nature. And that will be evidence that the stone has been heated.įor many semi precious gemstones, it’s almost impossible to know whether it is heated. However, the inclusions in them, which are other minerals, sometimes melt or explode under such high temperature. They are often heated to higher than 1000°c. Ruby and sapphire can withstand high temperature. Their heat treatment is usually detectable. The signs of heating usually appear only when the gem is heated to a high temperature like for ruby and sapphire.

DOES HEAT TREATED AMETHYST FADE IN SUN HOW TO

‍ How To Know If Gemstone Is Heat-Treated?Īlthough it’s not difficult to look for signs of a gemstone that has been heated, a lot of the time it’s impossible to know that it has NOT been. So now if a seller tells you the aquamarine that they sell is unheated, you should take it with a grain of salt. More times than not, the treatment is not detectable. Heat treating a stone can improve its color and clarity. This causes cracks which may lower the value and durability. However, with high temperature like the case for ruby and sapphire, the gem may become “slightly more brittle than usual, and care must be taken not to damage pointed faceted corners and edges” according to this GIA article.Īlso, some other mineral inclusions inside the gem may expand more than the host gem. Heat treatment with a lower temperature doesn’t have any drawbacks most of the time. And sometimes it changes the color so dramatically that the heated stone is given a new name, like in the case of tanzanite. And it doesn’t mean the heated gemstone is lower in quality or less authentic.Īs you can see from the commonly heated gemstones from above, heat treatment can improve a stone’s color to a more desirable one (according to market’s demand). Many consider the treatment as an extension of the natural process.Īs long as the seller is transparent, and the color by heating is permanent (which it usually is), heat treatment is widely accepted in the gemstone industry. Not at all, heating gemstones have nothing to do with whether the gem is genuine or not. ‍ Does Heated Gemstones Mean They're Not Real?

Does heat treated amethyst fade in sun