Presidium Duo gem tester (model PDT-II)

Summary Bench model. A dual tester with both thermal meter and reflectivity meter. Sale price, offer ends 5 August.  Place the probe on the stone to operate analogue meter (the thermal meter, see detail in the extra pictures). Place the stone over the sensor (even if it's in jewellery) to operate the digital meter (the reflectivity meter).  You don't have to use both systems, you can choose one or the other. Guarantee: 1 year Details The thermal meter works with any stone, loose or mounted in jewellery, even uncut stones. The only condition is that the stone (and tester) must be at room temperature. It is the same as the basic Presidium model (thermal meter only),  it tests for 17 common groups of gemstones (about 40 varieties),  enlarge the product picture to see the scale in detail.  The reflectivity meter works on loose (not mounted) stones with a perfectly flat, perfectly polished surface, than can be rested over the sensor, it is not affected by temperature.  Disclaimer All testers  must be used in conjunction with the user's skill, knowledge and experience. Under no circumstances shall QUICKTEST be liable for direct or indirect loss sustained in connection with any item. Nothing is 100% accurate, you must understand the limitations of any tester you buy. We also suggest you regularly test known samples to check for any obvious faults. Full support given for items you buy from QUICKTEST. Alternative gem testers Please note, none of these testers will distinguish natural stones from synthetic stones. "Synthetic" is a scientific term meaning 'made by man in a factory/laboratory to the same formula found in nature', the two are usually indistinguishable.  Model Tests mounted stones [1] Tests  Diamond Tests  Moissanite Tests Ruby /  Sapphire Other stones Handheld presidium gem tester (GEMTEST-PGI) ✔ ✔ Shows up as diamond ✔ 31 stones Standard Presidium (GEMTEST-P2) ✔ ✔ Shows up as diamond ✔ 17 stones Digital refractometer by Presidium (REFRACT-DIGI-PRESID) ✘ ✔ ✔ ✔ 55 stones Refractometer (optical not electronic) (Refract-L) ✘ ✘ ✘ ✔ Hundreds of stones [4] [1] All testers test loose stones but not all can test mounted (set in jewellery) stones. [2] The probe / analogue meter will test mounted stones, the digital meter will only test loose stones. [3] The probe / analogue meter: 17 stones; the digital meter: 40 stones. [4] Skill and practice is required to use an optical refractometer, instructions are not included, see any textbook about gemmology…or the internet.