The purpose of this page is to take you through every possible reason why you might be having problems with a diamond tester, Moissanite tester or Multi tester. Easy to use, compact and sturdy, the Presidium diamond testers provide accurate and consistent results every time. As a diamond tester manufacturer, we also welcome new distribution partners to join our growing business. Go to our downloads page, scroll down to INSTRUCTIONS FOR DIAMOND AND GEM TESTERS, find the instructions for your model of tester.

The other gem testers (above) display the result as a number you must look up on a chart; this reflectivity meter displays the reading as refractive index. This is important because metal will register as diamond on most diamond testers that lack the metal detector feature. The ASSURE program is an individual and trusted association that conducts thorough testing on natural diamond testers in the market. If you are not using it at room temperature you must calibrate it (not difficult but it does take several seconds); it really will not work at all if it's very cold (e.Suitable to use with loose and mounted stones, gauges are designed to provide accurate measurements and instant results. If your tester works consistently (it gives the same reading on the same stone every time) and correctly (it accurately identifies stones) then you really don't need to know the principle on which it works. There are diamond testing devices for detecting loose or mounted stones, like the Gemlogis VISTA and VISTA PRO.

It is also particularly easy and fast to use and can be used on any stone no matter how it might be mounted. Plastics (and, to a lesser extent, glass) feel 'warm' whereas sapphires, rubies and diamonds feel icy cold. Gem testers merely suggest possibilities and you must use a combination of experience and other tests to come to a conclusion. However, it is worth mentioning that electrical conductivity diamond testers and multi-testers are much better than thermal conductivity testers. your supplier of new jewellery has sent you ten sapphire rings and you want to check that they are all the same.

Presidium are the leading provider of gemstone testers and gauges designed to provide jewellery makers with the tools they need to ensure that they can verify loose and mounted gemstones with accuracy.

If a stone is very hot, it will feel warm-to-the-touch even if it is diamond, and will not register DIAMOND on a diamond tester.

GIA instrument developers include scientists, engineers and jewelers who use the very instruments that they develop. The SAFFRON is a highly popular product amongst diamond producers, wholesalers and jewellers working with gemstones or melee diamonds. Most of Gemlogis's handheld diamond testers for sale feature a function that connects wirelessly to the BLEU (sold separately). You can also see, from the principle that you can accidentally make a circuit and get a MOISSANITE reading: by touching the setting of the jewellery, OR by placing the probe tip very very close to the setting so that the electricity 'jumps' - which is why you can't test very tiny stones (e.