‘Madam, do you have any jewelry that matches my nail polish?’
I was asked this question at an art market this summer and the lady showed me her more than bright pink nail polish. That polish was dazzling and the lady in question was pleased with it. She was parading around with it at that art market.
Nature and gemstones determine the colors in which they appear, not the nail polish that was in fashion at that time. I could not help her with that color gemstone in a piece of jewelry.
Nature determines the color of a gemstone, but sometimes people want to give nature a helping hand and that can be done in many ways. You must know that the color of a gemstone can be ‘processed’ and that you buy a treated gemstone instead of a natural one.
A processed, colored, or treated gemstone can reduce the value of a piece of jewelry, but that is not necessary. It does not have to be a problem if a gemstone is processed if you prefer that, but you must know that this is not entirely the natural color of the gemstone. You have a choice.
Some gemstones come in many colors, such as agate. But to get a gemstone in a certain color, those stones are also dyed. And then the gemstone gets a completely different color. So not just a little bit of coloring, but just dyeing a white gemstone turquoise, for example.
That is only possible if a gemstone is porous, otherwise the dye will not hold. Howlite in particular, which is originally white, and lava stone are porous enough to dye. And the quality of those gemstones can be quite good. Even if they are dyed.
The problem is that howlite is usually dyed to sell this stone as turquoise, which is a very expensive gemstone. Sellers make a lot of money from that, but you are cheating your customers. Dyed howlite can be beautiful, but you have to know that it is not the original color and that it is a treated gemstone.
Another possibility is that the gemstone is not fully dyed, but only slightly dyed. That dyeing is only done to make the stone more saleable. The customer wants an even color or just a shade different.
An example of this is lapis lazuli. This very beautiful gemstone is deep blue with gold specks in the stone. But sometimes also white spots, which the customers do not like. By coloring the lapis lazuli, the stone becomes deep blue again. Unfortunately, the beautiful gold specks, which give the stone a beautiful appearance, often disappear with those treated gemstone lapis lazuli.
Although agate, for example, occurs in many colors in nature, the agate can also be colored. In nature, agate occurs in a blue or pink color, but then they are more pastel colors. If an agate has very bright colors, it is usually a colored and/or treated gemstone.
The same applies to carnelian, a gemstone with an orange to brown color, which is also called red agate, which is colored to get a more intense color. The black onyx and the brown-red sardonyx are also often colored.
The coloring of gemstones has been done for a long time and is certainly not a phenomenon of modern times. In the tomb of Tutankhamun, a colored red agate, or carnelian, was found. Pliny the Elder (23/24-79 AD) was a Roman scholar who described in one of his books how to color chalcedony by boiling it in honey.
In the 18th and 19th centuries, gemstone cutters in Idar-Oberstein/Germany already knew how to color agates. That was a precise job because agates are made up of bands, which have to be colored separately.
You can also give gemstones a heat treatment by exposing the gemstone to very high temperatures so that the clarity is increased and the color changes. This treatment is usually done to make the gemstones lighter or darker in color or to get a deeper color.
Without heat treatment, there would be far fewer gemstones on the market that have the color desired by the customer. And then we are talking about a treatment with temperatures of over 200 to 1000 degrees Celsius. Aquamarine, amethyst, blue topaz, blue zircon, citrine, but also ruby, sapphire, and tanzanite are often treated with heat. Untreated gemstones are up to 50% more expensive than a treated gemstone.
A good example of a treated gemstone is citrine, which is very rare, but still quite common on the market. They have found a solution for this: if you heat an amethyst to over 500 degrees Celsius, it turns yellow and you can pass it off as a citrine.
An amethyst can be heated to get a lighter color. With a little more heating, the color becomes deep purple to orange-yellow (citrine). And if you go even further, all the color has disappeared from the amethyst, or it has a milky color.
However, some amethysts turn green when they are heated. Then this gemstone is called prasiolite.
When a ruby is heated, the color changes to, for example, red-purple, and the clarity is improved.
Gemstones that cannot be treated with heat are emerald, garnet, peridot, opal, ametrine, and spinel. This heat treatment is a risky process because many gemstones have inclusions with different expansion coefficients, which can cause cracks in the gemstone.
Another form of processing the color and appearance of gemstones is electroplating. A layer of silver or another metal is then placed over a gemstone, which makes the color more metallic. Multiple colors can also be placed on the base of the gemstone. The gemstone also becomes stronger.
Examples of this are the rock crystal in the blue necklace. The icicles are yellow electroplated. Or the silver layer over the lava stone, which ensures that the black lava stone gets all the colors of the rainbow. A good example of gemstones that have been given a coating via electroplating is the Aura stones which usually have a rock crystal as a base, which is heated in a vacuum and provided with a coating of gold, silver, titanium, niobium or other metal oxides.
An aura stone or quartz is a special type of quartz that has a lively iridescent color, such as rainbow quartz or angel aura quartz, and to which spiritual properties are attributed.
The color of blue topazes, but also diamonds, tourmaline, and pearls can change with treatment with electron, neutron, or gamma rays.
Laser drilling can remove small impurities from diamonds, for example, which significantly increases the price of the diamond. A thin line is then drilled into the impurity with the laser, which is dissolved with a chemical agent. The diamond appears purer after the treatment. For example, if rubies or sapphires are full of tiny cracks or holes, they are filled with lead glass. That lead glass has the same refraction or light refraction as the gemstones mentioned and it is therefore not visible that they are filled with glass.
In fact, you are cheating, because you are not buying rubies or sapphires but sometimes up to 50% glass. That glass discolors during wearing and it can scratch, because the glass is softer than the original gemstone.
The same applies to emeralds. Here, certain oils or synthetic filters are used to fill the cracks and holes. That filling material can discolor or even evaporate during wearing and over time and then the gemstone has to be treated again with filling material.
You can agree or disagree with treated gemstones by coloring, dyeing, heating, or electro-plating. You then get the color you want, but it does not have to occur in nature.
In itself, I don’t think it is that bad, as long as it doesn’t happen too much, but if you buy such a treated gemstone, you should know in advance that the color of that treated gemstone is not ‘made’ by nature. You then have the choice to buy that treated gemstone or not. That’s up to you! FlorenceJewelshop has created a PDF with all the natural colors of gemstones. You can download it for free by clicking the button.
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