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Crystal Salt


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  • Can Gemlogis testers replace Lab Tests?
    No. Tests performed by devices of Gemlogis are not equivalent to a gemology lab test. Its function is designed to provide a quick indication and reference based on industry-approved technology.
  • Why choose Gemlogis Diamond Testers?
    Gemlogis results are highly accurate providing all the criteria are met and that the devices are handled accordingly. Certain products of Gemlogis has been certified by the ASSURE Tested Certification Mark as one of the best portable diamond testers. Gemlogis testers are not designed to replace Lab Tests, it is only to provide a quick reference based on industry-approved technology.
  • How reliable are Gemlogis products?
    Gemlogis uses industry-approved technology that has been widely used for over 20 years. Our R&D office is based in Singapore and our production facilities comply to ISO9001-2000, ISO14000, and ISO 13485 standards. Gemlogis products have also been tested and quality-checked by third-party certification standards.
  • How to identify earth-mined diamonds?
    Gemlogis utilizes different technology to identify and segregate earth-minded from synthetic diamonds. It is scientifically proven that Type IaA and IaAB diamonds absorb short-wave ultraviolet light (SWUV) while Type IIa and IIb transmit SWUV light. Gemlogis have developed products specifically to identify potential synthetic (CVD/HPHT) lab grown diamonds whether they are loose or mounted.
  • Why I am getting inconsistent results?
    Gemlogis testers require a certain level of user experience to handle properly: Make sure to clean the probe tip and remove oxidation Make sure to clean the surface of the gemstone to remove any grease and dirt Make sure the gemstones are at room temperature (remove from body/pocket to let it cool down) Make sure to point the probe tip at a perpendicular angle (90 degrees) against a flat surface of the gemstone Make sure your hands are clean and free from creams and lotion. Always hold the metal on the tester and the metal on the setting. For loose stones use a metal tweezer or stone rest (provided) Make sure to allow the gemstone to cool down between consecutive tests Make sure to test different spots on the surface of the stones, due to the impurities on the stones, it may affect the results.
  • Why does moissanite indicate as diamond on some occasions?
    In some instances there may be a disproportional allocation of silicon carbide located on a moissanite; therefore, performing several tests on different spots (including the girdle) of the gemstone is recommended.
  • Can Gemlogis thermal testers detect uncut raw/uncut stone?
    Yes, as long as the stone has a clean & flat surface.
  • Will the size of the gemstone affect the test result?
    Yes. Smaller stones conduct less heat from the probe tip. Hence, the reading indicated may be slightly lower.
  • Why do blue diamond & black diamond indicate as moissanite or metal?
    Blue Diamond is a semiconductor due to the substitution of boron impurities in place of carbon atoms. Black Diamond is substituted with graphite or iron inclusions. Both blue and black diamond will indicate as moissanite or metal on the tester.
  • Why do I sometimes hear intermittent beeping when testing gemstones?
    Whenever the probe tip touches a metal surface, an intermittent beep will sound. This is only applicable to mounted gemstones.
  • Why is the meter indicator not reverting back to zero?
    It could be static charge on the surface of the meter. Please wipe the surface of the meter with a damp tissue to discharge the static electricity.
  • Can the Colorstone Meters identify synthetic and natural stones?
    Due to the same formation of the chemical composition of synthetic and natural colored gems, the thermal inertia of synthetic stones has the same heat conductivity as natural gemstones. Colorstone meters cannot distinguish between synthetic and natural gems by testing their thermal inertia only. For identifying natural diamonds, please refer to our synthetic segregators.
  • Can Colorstone meters identify the exact stones?
    Our meters only provide the heat conductivity reference of various stones. Prior to testing, the user must be aware of which specific type of gemstone they are handling, then as a reassurance, use our meters to confirm its identity.
  • Why do I get inconsistent readings from Colorstone meters?
    It is possible to get inconsistent test reading if your stone is too hot or too cold. Always test a stone at room temperature. The tester tip produces heat and can warm the stone. Heat conducts from the probe tip to the stone, the tester measures the amount of heat conductive to the stone. The reading falls once the heat saturates the stone. Try placing the stone on the stone rest (provided) to enhance the heat conductivity. Always allow the stone to cool down for a while for subsequent tests.
  • My colorstone meter is not responding to the Diamond Tester wirelessly
    Begin by making sure the IR is turned on in your settings. Then, make sure the infrared connectors on both devices are pointing towards each other and not obstructed in between.
  • Where to purchase Gemlogis products
    Gemlogis products are sold by distributors throughout the world. Please see the North American distributors located on our distributor page or contact us for additional information at:
  • How long is the warranty?
    Gemlogis products comes with a 12 month factory warranty.
  • I purchased the tester at an overseas expo, is it covered by factory warranty?
    Gemlogis does not provide warranty repairs directly. The customer must return the units to the reseller they purchased from in order to qualify for factory warranty terms. In the event you purchased the products from an oversea dealer, you must return to the said dealer.
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