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CSI Gemology, Part 1

I find that Gemstone identification is similar to being a detective. When first presented with a crime, the detective has a big list of suspects from which they interview for motive and opportunity. From there, they narrow down the list until they come to the culprit. A gemstone also has a big list of suspects it can be. A Graduate Gemologist will perform tests using various tools and make key observations to determine who the culprit, or gemstone is. Just as in detective work, sometimes it is obvious and easy to determine the gemstone, and other times, it feels like an educated guess!

The first step of gem identification begins with thoroughly cleaning the gemstone of dirt, oil, and fingerprints because they can give you false readings. The next step is Observation.


· Color: It is important to not only observe the main body color, like blue, but also if it is slightly greenish blue or very strongly greenish blue, for example. For the most part, gemstones aren’t only one of the colors of the rainbow, but they have variants of other colors in them which can make a difference when identifying it. Color alone can take suspects off the list, for instance, Peridot is always an apple green color, so if the gemstone is blue, you already know it can’t be that.

· Transparency: Gemologists use a strong light in a dark room to determine its transparency. Diamond is transparent because the light comes through it, while Turquoise is opaque because no light comes through. If it is opaque, you know it cannot be certain gemstones.

· Phenomena: Some gemstones display phenomena, like cat’s eye or color change, that can be found using a strong penlight or fiber optic light. In a dark room move the light over the stone back and forth to see if a cat’s eye or a star is found. You can also look at the gemstone in both daylight-equivalent light and incandescent light to see if the stone has color change. In my blog , I talk more about the color change phenomena!

· Dispersion: Dispersion is the gemstone’s ability to separate white light into its spectral colors. Some gemstones, like Sphene, have eye visible dispersion which make it easy to identify.

This is my first blog in a series on the gem identification process which I have done a lot of as a Graduate Gemologist. While Observation may not seem as exciting as the other steps, it is very useful in taking suspects off the list and narrowing down who dunnit, I mean, which gemstone it is! In the next step, we get to use my favorite tool! Let's get gem nerdy!

I would love to help you with your special purchase or custom design! Angela Cisneros Jewelry Concierge brings back the joy and confidence of jewelry shopping, so that you can celebrate with ease! My by-appointment approach means:

  • One-on-one appointments (personal attention and no crowds!)

  • Discretion and privacy (surprises remain surprises!)

  • Expert help from a Graduate Gemologist with 23 years of experience (yep, that’s me!)

Book your FREE appointment with me today!

Photo credit: @giagrams

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