Understand tourmaline identification by read this article and avoid being cheated!
As the darling of the gemstone world, tourmaline is deeply loved by many jewelry lovers for its rich colors and unique charm. However, there are a lot of different tourmalines on the market. How can we identify their authenticity and quality? The following is a detailed introduction to the identification methods of tourmaline. Among them, observation with identification instruments is the most effective method.
Distinguish by Observe the color
Tourmaline has a wide range of colors, including red, green, blue, yellow, purple and other tones, and even has two or more colors coexisting. The real high-quality tourmaline has bright colors, high saturation and uniform distribution. For example, the famous Lubrizol tourmaline has a rich red color; while the Paraiba tourmaline is unique with its charming blue-green tone.If the color is too dull, stiff, or unnaturally even, be careful.
Observe the texture through light
High-quality tourmaline has good transparency, but natural tourmaline will have some tiny inclusions inside, and it is extremely rare to be completely pure. When you look at an object through tourmaline, if you can see it clearly and there are some natural inclusions inside the crystal, it is most likely real. If the transparency is abnormally high and the inside is as pure as glass, it is likely to be a synthetic product.
Observe Luster
Tourmaline has a glassy luster and a smooth and bright surface. Gently turn it with your hands, and the luster is even and rich in texture. The luster of fake tourmaline is often harsh or too shiny, lacking the natural agility.
By Identification instruments
1. Refractive index test: The refractive index of tourmaline is 1.624-1.644, measured by a gem refractometer.
- Optical property detection: Uniaxial crystal has negative optical property, which is measured by gem polariscope.
- 3. Hardness test: The Mohs hardness of tourmaline is between 7 and 7.5, which is similar to the hardness of crystal. You can use a copper key (Mohs hardness is about 3) to gently scratch it. The surface of real tourmaline will not leave obvious marks, while materials with low hardness such as glass will be easily scratched. But please note that this method may damage the gemstone. It is more suitable for the identification of raw stones, and it is best not to use it on finished gemstones.
- 4. Density judgment: The density of tourmaline is usually 3.06 – 3.26 g/cm3. It can be preliminarily judged by precise measurement with a density balance.
- 5. Thermoelectricity experiment: When tourmaline is heated or rubbed, electric charges will be generated at both ends of the crystal, which can absorb small pieces of paper and other light objects. However, this method is greatly affected by the environment and is not very stable.
- 6. Pleochroism experiment: When observing tourmaline with a dichroscope, you can see images of two different colors or different shades of color. This is the double refraction phenomenon of tourmaline.
- 7. Inclusion observation: Observe with a magnifieror microscope. Natural tourmaline often contains gas-liquid inclusions, mineral crystal inclusions, etc. The gas-liquid inclusions are irregular or tubular in shape, and the mineral crystal inclusions may be mica flakes, feldspar, etc. The inclusion characteristics of tourmaline from different origins are different. For example, Brazilian tourmaline often contains pyrite inclusions.
By gemstone identification institution
If you are really unsure, the safest way is to send the tourmaline to a professional jewelry identification institution. Professional appraisers will use various precision instruments and professional knowledge to conduct a comprehensive and detailed appraisal and issue an authoritative appraisal certificate. With a certificate, buying tourmaline is more secure! Mastering these identification methods, I believe that when you choose tourmaline, you will be able to have a keen eye and choose one you like and of high quality!