Presidium Gem Tester II Gemstone Tester

Gemstone tester for coloured stones

The Presidium Gem Tester II gemstone tester uses thermal conductivity to help separate up to 16 common coloured gemstone categories. This gemstone tester provides an analogue reading and built-in reference discs; it is a screening tool and should be operated according to the Presidium handbook.

Gemstone tester probe and calibration

The Gem Tester II gemstone tester has a retractable 0.6 mm probe tip that Presidium says can test stones from 0.02 carat. This gemstone tester should be calibrated on its reference discs and used at the recommended ambient temperature to reduce avoidable reading errors.

Gemstone tester interpretation limits

A gemstone tester based on thermal conductivity cannot distinguish natural from synthetic coloured stones, as Presidium states. This gemstone tester should therefore support, rather than replace, further gemmological observations or laboratory testing when a stone’s origin or value matters. See Presidium’s gemstone testing guide for more about gemstone testing.

Product video