PRESIDIUM Gem Tester II Mode D'emploi page 6

III. About your Presidium Gem Tester II
The Presidium Gem Tester II is based on the invention
of Professor Julian Goldsmid from the University of New
South Wales in Australia. It was developed to distinguish
between diamonds and its other simulants using the
principles of thermal conductivity.
Diamonds, with their exceptional heat conductivity
properties are unlike any other simulants, and are
therefore not easily replicable.
The Presidium Gem Tester II probe consists of two linked
thermometers: one, which is heated electronically, while
the other is cooled by the gemstone being tested. The
difference in temperature creates an electrical output,
which is then amplified and displayed on an analog dial.
The Presidium Gem Tester II is now equipped with
a Color Stone Estimator display to assist the user in
distinguishing popular colored gemstones from each other.
It is to be noted that natural and synthetic gemstones
have similar physical and optical properties. As such,
Presidium Gem Tester II does not distinguish between
natural and synthetic gemstones.
As with all thermal testers in the market, the tester is
not able to differentiate between natural Diamonds and
Moissanite.
The Presidium Gem Tester II has been subjected to
thorough factory quality control, and will
generally give a clear and reliable reading of the
gemstone being tested under proper use. However,
you are advised to conduct further supporting tests.
5