High Accuracy Diamond Tester Professional Jeweler For Novice and Expert - Diamond Selector II 9V Battery Included

Product Information

Do not test the same stone repeatedly, until it becomes hot. A hot stones will not register 'diamond', even if it is. Inconsistent readings miraculously become consistent if you wait a minute or two for the stone to cool down. Natural diamonds grow, naturally, deep in the earth as 'rough' diamond crystals (mined diamonds). Synthetic diamonds are grown by man in a laboratory. Synthetics and naturals are identical, they are both diamond. That is why it is so difficult to tell them apart; that is why these testers are expensive. Find out more about this at our guide to synthetic-diamond testing . the stone must be transparent and must have perfectly flat, perfectly polished top (table) which will fit over the sensor hole; if the stone is tiny (under 3mm) you will struggle to get a reading; if an item of jewellery is too large (or lumpy) you won't be able to rest the stone over the hole it is a sensitive piece of laboratory equipment, it must be kept clean and dry, the sensor must be kept dust-free, it must not be bumped in and out of bags or used on damp outside market stalls

Gives correct results about 95% of the time (6% false positive rate, 4.5% false negative rate) providing the colour is 'clear' (colour D to J) and the size is at least 0.02ct and the cut isn't shallow. Thermal testers work on heat. Their advantage is simplicity, touch the probe on the stone, see the reading, no skill and no special training is required. Disadvantages: they only work at room temperature (typically between 19 and 26 degrees C); they only test for a few stones and (as you see from the picture below) many of the readings overlap. it is an extraordinarily sensitive thermal conductivity meter, and is therefore very sensitive to heat. 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.g. outside in the winter in Northern Europe) Additional gems besides diamonds have high conductivity (such as moissanite) but a diamond tester can separate a diamond from a cubic zirconia. The latest diamond testing devices combine heat and electricity testing so they’re the most accurate. Reflectivity / Refractive Index testers are optical not thermal (so they work at any temperature), they help identify many dozens of stones.NO REACTION, if it's low thermal thermal conductivity (those that never give a reading on a standard diamond tester) - it could be anything, but it's not diamond The Presidium ARI is an essential tool for the experienced jeweller and professional diamond dealer, it is for testing known diamonds. So if you are testing a really tiny stone and get a reaction, it's probably diamond (test it again, turn the sensitivity right up). Do not confuse 'synthetic' with simulant/imitation. Read all about it at Testing for Synthetic Diamonds. You might be curious how diamond testers work. It tests the stone for its thermal and/or electrical conductivity. Thermal conductivity diamond testers measure the amount and speed that heat travels through the stone. Electric conductivity testers measure the amount and speed that electricity travels through the gemstone.

Diamond testers help to separate real diamonds from anything else. Lab-grown diamonds are identical to natural ones in their crystal structure, chemical composition and physical properties. This means they also have the same thermal and electrical conductivity properties, so lab-grown diamonds test positive on any type of diamond tester.The Presidium ARI will distinguish most synthetic diamond from natural diamonds. It will also detect Moissanite. The Presidium ARI is not a diamond tester for distinguishing diamond from non-diamond, if you need a 'diamond tester, you can find the product here, or see our general guide to buying diamond testers. Stones must be Brilliant Cut (modern, round) and perfectly-cut in proportion, it will not test shallow stones. For the non-expert: make sure the stone is recent (eg not from the 19th century) and is round. For the professional jeweller: if you specialise in Victorian jewellery (or earlier) this tester might not be suitable, it will not give accurate results on rose-cut etc. Easy to use, compact and sturdy, the Presidium diamond testers provide accurate and consistent results every time. Presidium Gauge