![]() You can find one online if you don’t already have one. ![]() These tools are valuable for gemologists since they allow quick ways to eliminate possibilities when checking stones out. This is a one-way test: dichroism can prove a stone is natural, but not having it doesn’t mean the stone is heat-treated.Ĭhecking for dichroism requires a specialized tool, a dichroscope. Dichroism is an optical effect created by the crystals, stones will shine with different colors depending on the orientation of the crystals. Some of the natural forms of citrine exhibit dichroism that amethyst does not. They still have other tell-tale signs but this is the quickest way to start identifying the piece. These specimens were very common in the rock trade not long ago and there are a lot of them bouncing around. Just note that if it looks like it was cut from the exterior of a geode, chances are it’s not citrine. Citrine is often in the same formation as regular quartz, so clear bits aren’t a deal-breaker. You’re most likely to see smaller crystal formations. The majority of natural citrine samples will be smaller points or other formations, it very rarely forms in geodes. One of the most common treated amethyst displays I’ve seen is crystal formations from the inside of large geodes. In general pale yellow specimens with color-zoning are the most common natural citrine. As if this whole thing wasn’t confusing enough. The difference can be subtle, and there’s also some overlap. Heat-treated specimens will tend to be more on the orange-yellow side of things, while natural specimens often a gold or straw yellow instead. If the piece is a single uniform color then it may be man-made, especially if the price seems reasonable. Solid colors can also be a bad sign, especially if it’s through a relatively large piece. No natural citrine is colored that way and it’s perhaps the most definitive way to find out a specimen is heat-treated amethyst instead of citrine. The important thing to look for in the specimen is “burnt” looking tips to the crystals. Heated stones will have color changes throughout them. If the stone is already faceted, you’re probably out of luck on finding out if the stone is natural in origin this way. Check the ColorationĬolors are the biggest tell. Here are a few different things you can look at to help determine if what you have citrine or heat treated amethyst. ![]() Heat-treated amethyst is almost identical to naturally forming citrine. There are a couple of good indicators, but telling them apart isn’t always possible. How To Tell Heat Treated Amethyst vs Citrine With its desirable coloration, we’ve got a problem on our hands for collectors it has become a common practice to heat amethyst to the point where a change in coloration occurs, causing the heat treated amethyst to look just like citrine. ![]() It should be noted that citrine is very rare in nature, unlike amethyst. The charge of the Fe ion changes with temperature, altering the color of the stone. Natural occurring citrine is relatively rare since it requires higher temperatures to form. These crystals form at the following temperatures: Of these, prasiolite is the rarest since it forms only in a narrow band of temperature between amethyst and citrine. There may even be multiple causes of the coloration.Ĭitrine is a gem name, not a scientific classification. As long as the gem is colored yellow or orange through, and not just on the surface by something like ferrous oxide, it can be called citrine. The above is the most common explanation found, and the one I tend to agree with. Please note that there are a few trains of thought on how citrine acquires its color. They are amethyst, prasiolite, and citrine respectively. Depending on the formation temperature of the stone, you end up with one of three different forms of quartz. It’s known for its hexagonal shape and sharp terminations at the end of the crystal.Ĭitrine is a form of quartz that has iron in the color centers of the crystals. Silica makes up a large amount of the earth’s crust, and quartz is one of the most iconic crystals around. Quartz is silica, SiO₂, with a macroscopic crystal form. ![]() It’s almost identical in physical makeup to amethyst, but differences in the original formation of the crystal cause it to take on a different color. Citrine is a variety of quartz that’s colored yellow to orange. ![]()
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