Our selection of Gem ID Tools are summarized below. Click on the
pictures or hyperlinks below, or the navigation buttons above for detailed descriptions,
or to order any of these products.
Gem-n-Eye
Digital Refractometer
A Digital
Refractometer that uses the reflectivity of Faceted
gemstones to confirm their identity. It gives a digital readout
in the form of a Refractive Index to 3 decimal places, along with the Gemstone
names that share that RI value! The Gem-n-Eye covers the entire R. I. range, from Glass and
Colored stones, thru Diamond and it many simulants. Use with Loose
and many Mounted stones. The Gem-n-Eye has an internal database
of over 200 gemstones, and also functions as a Gemstone
Computer, performing a combination search of 9 key properties of a gemstone
to aid in identifying it.
Price: $425 - Now available!
Presidium Reflectivity Meter
An economically priced, basic reflectivity meter, with a digital readout
of a reflectivity value which
you cross-reference to a particular gemstone. For use on Faceted stones
only, loose or mounted, but this instrument tests across the whole range of
gemstone species, from
lowly Glass, through the full range of Colored stones, into the Diamond
simulants, and through Diamond and Synthetic Moissanite.
Price: $175
Presidium Refractive Index Meter II
An advancement over the Reflectivity Meter - Presidium
has converted the digital readout to an actual RI value displayed to 3 decimal
places. This meter comes with USB connectivity and computer Software that
includes a Gemstone Database, Lookup and Property Search functions. Like the
Reflectivity Meter, the PRIM II is for use on Faceted stones
only, and covers both the Colored Stone range as well as High Index stones.
Price: $279
Presidium Gem
Tester/
Color Stone Estimator
This instrument is like a thermal conductivity probe as
historically used on Diamonds, but now engineered for use on
Colored gemstones, with an analog meter readout where the needle points to the
identified gemstone(s) species. It works on Loose or Mounted Faceted
stones,
but unlike the Reflectivity meters, can be used on Cabachons as well, along with
Gemstone rough.
Price: $219
Presidium DuoTester
The DuoTester combines the features of the Reflectivity Meter
and the Gem Tester into one instrument, measuring both Reflectivity and Thermal
Conductivity. It is the
only tool on the market that provides the user with two proven tests for Diamonds
and the ability to differentiate between similarly Colored gemstones. Can
be purchased with or without a set of seven species of faceted Diamond simulant
gemstones.
Price: $349 to $449
Gemological
Refractometers
The standard gem ID instrument, used to measure Refractive
Index and Birefringence of gemstones up to 1.81 R.I. The
Refractometer is known for its accuracy and
consistency. We offer 2 models to choose from, Professional and
Economy grade, along with Refractive Index
Fluid.
Price Range: $219 to $509
A simple and affordable tool for separating many Colored gemstones. These
filters are designed to transmit only certain colors of light, so when the user
looks at a stone through the filter, he or she observes the apparent color of the stone and matches that up with the
identifying chart that comes with the filter. We offer 4 different
filter selections, including the renowned Chelsea Filter.
Price Range: $28 to $64
Incorporates a precise digital
calipers to measure the size of a gemstone, adds to that your input of the type
of gemstone cut, and uses that data to estimate weight. Or, if you provide
the weight of a stone, this tool will also estimate specific gravity, and
retrieve matching gemstones from its internal database, and thus aid in
identifying unknown stones.
Price: $249
Use a dichroscope to determine
Dichroism and Pleochrosim of gems as an aid to identify them.
Price: $69
Buying Guide to Refractometers versus Reflectivity Meters:
A Refractometer measures a gem's Refractive Index (R.I.)
and Birefringence, the former by essentially passing light through the
stone, and where that light refracts out at a defined and consistent angle
based upon that gemstone species' makeup.
A Reflectivity Meter essentially bounces light off the surface of
the stone, measures that degree of reflectivity or luster, and
converts that into a readout.
Pros and Cons:
Refractometers are accurate and consistent, and
therefore the first instrument of choice among professional gemologists.
However, they require the use of R.I. Liquid which is smelly,
potentially toxic, and a
little inconvenient. Furthermore, almost all refractometers have a maximum
limitation of 1.81 in R.I., thus excluding high index stones like some
Garnets, Zircon, Diamonds, and various Diamond simulants. So in effect,
Refractometers cover mainly the range of so called Colored Stones.
It should also be said that advanced gemologists can use Refractometers to
measure some cabochons, in addition to faceted stones of course.
Reflectivity Meters are less accurate and consistent than
Refractometers, leading to more overlap among possible gemstone species, and
therefore requiring secondary tests for reliable
identification. Having said that, Reflectivity Meters are fast and easy
to use, and require no messy liquid. Furthermore, they have no
limitation on the range of stones - they can measure anything from lowly glass
all the way up to and through Diamond and its simulants. Reflectivity
Meters can be used only on faceted stones.
Calcite
Dichroscope