ARI by Presidium

ARI is developed as a handheld PRESIDIUM DIAMOND VERIFICATION INSTRUMENT® to help identify colourless diamond against CVD/HPHT lab grown colourless diamond and all types of moissanite.

It is suitable for testing on both loose and mounted stones, including jewelry pieces with a closed back setting.

Through advanced proprietary technology, ARI measures the UV light absorbance ability of diamond and moissanite. With its touch screen colour LCD display, ARI provides a clear and accurate result of “Diamond”, “CVD/HPHT/Type IIa” and “Moissanite” within 3 seconds.


*PRESIDIUM DIAMOND VERIFICATION INSTRUMENT is a registered trademark of Presidium Instruments Pte Ltd.

Duo Tester II (PDT II)

Introducing Presidium’s Assisted Thermal Calibration (ATC) function using newly redesigned in-built calibration discs to ensure accurate and consistent tests for both indoors and outdoors operation.

Presidium Duo Tester II (PDT II) is the only comprehensive tool on the market that combines two proven testing methods for gemstones. PDT II differentiates diamonds from its simulants based on both their thermal conductivity and reflective indexes. Coated gemstones can also be generally tested with the PDT II.

The Presidium Duo Tester II comes with a probe pen that has a retractable probe tip which ensures consistent pressure against the gemstone during testing for more reliable results. With the industry’s thinnest probe tip size of 0.6mm, PDT II tests gemstones as small as 0.02ct.

*Does not differentiate between natural and synthetic colored gemstones.

Carat Scale (PCS-100n)

The new and improved PCS-100n measures gemstones up to 100.00 carats and no longer needs to be calibrated each time the scale is shut off

The Presidium Carat Scale – 100n utilizes advanced circuitry design and surface-mount technology to weigh diamonds & precious gemstones up to 100.00ct precisely, for long periods of continuous usage. Each scale comes with its corresponding weight reference of 100.00ct/20g for calibration.

This compact and portable scale no longer needs to be calibrated each time the scale is shut off and can also be powered by a USB adaptor.


Developed by Presidium to identify diamonds against a wider range of moissanites, including the new “low conductivity moissanite”, and other diamond simulants through its highly sensitive thermoelectrical probe.


SAM is the latest technological advancement in handheld diamond & moissanite testers  by Presidium that reliable and accurately verifies the authenticity of colorless diamonds, as small as 0.01 carats, against a wider range of moissanites from various countries and other diamond simulants through a higher resolution of thermal and electrical conductivity. Showcasing a sleek chrome brushed ergonomic grip and dynamic micro LED display, SAM ensures ease of usability and distinctly clear result display while testing.

With the industry’s fastest start-up and testing time, SAM only utilizes technology that does not compromise user safety that does not require harmful Ultraviolet (UV) light.



Gem Tester II (PGT II)

The industry’s most trusted colored gemstone tester is now redesigned to be more compact, sturdy and portable.

In it’s second generation, the Presidium Gem Tester II provides a quick and easy way to identify diamonds/moissanites and separates up to 16 common colored gemstones based on their thermal conductivity with its clear and direct analog display. A newly redesigned inbuilt calibration reference and adjustment provides ease of operation both indoors and outdoors.

The Presidium Gem Tester II features the industry’s thinnest retractable probe tip (0.6mm) for testing colored gemstones as small as 0.02 carats. Coated gemstones can also be generally tested with PGT II.

*Does not differentiate between natural and synthetic colored gemstones.

Synthetic Diamond Screener II (SDS II)

Enhanced with additional features, the Synthetic Diamond Screener II now tests for diamond melees as small as 0.02 carats with instantaneous results, through the measurement of UV absorption.

The Synthetic Diamond Screener II is developed as a portable PRESIDIUM DIAMOND VERIFICATION INSTRUMENT® to help screen out Type IIa colorless diamond, which is likely to be laboratory-grown and created through chemical vapor deposition (CVD) or high pressure high temperature (HPHT) syntheses, from the natural Type Ia colorless diamond.

When subjected to this deep UV irradiation, Type Ia and Type IIa diamonds each absorb different amount of UV light. Type IIa diamonds allow deeper UV light to pass through and thus its UV light absorption ability is low. This difference in the light absorption is significant enough to aid in differentiating between colorless Type Ia and Type IIa diamonds.


*PRESIDIUM DIAMOND VERIFICATION INSTRUMENT is a registered trademark of Presidium Instruments Pte Ltd.

Gem Computer Gauge (PGCG)

An advanced digital computer gauge that measures gemstone dimensions and can estimate gemstone weight and identity for 9 different cuts.

Presidium Gem Computer Gauge measures the dimensions and estimates the weight of loose and mounted gemstones with precision, speed, and ease.

It is the only gauge in the industry that is able to give direct estimation of the weight of various gemstone of a range of 9 popular cuts, giving users the convenience of not having to dismount their gemstones from its jewelry settings.

After entering the weight and the measurements of a gemstone, the Gem Computer Gauge is alternatively also able to be used to estimate the identity of the gemstone, by computing its S.G. value and referencing the internal stored database.

With PGCG’s computer interfacing, gemstone measurement records can be easily imported and printed. PGCG also comes with a software that lists the S.G. value, R.I. value, and hardness measurements of 133 common gemstones in the market for handy reference.

Synthetic Ruby Identifier (SRI)

Instantaneously identifies synthetic rubies through its high UV transmittance.

The Synthetic Ruby Identifier by Presidium is a ground-breaking desktop device that instantaneously identifies synthetic (flame fusion) rubies through its characteristic high UV transmittance. Utilizes UV light with auto cut-off and gives quick results with clear indicator lights to measure the UV transmittance ability of ruby gemstones.

Works on both single mounted stones (with open-back setting) and loose rubies.

Refractive Index Meter II (PRIM II)

Desktop digital tester that uses refractive index to quickly separate gemstones, diamonds, moissanites and other diamond simulants.

By measuring the quantity of light reflected through the stone, the Presidium Refractive Index Meter II (PRIM II) is able to separate diamonds, moissanites and other colored gemstones via the Refractive Index (R.I) of these polished gemstones.

Unlike a traditional refractometer that has a limited range of R.I measurements and thus cannot be easily used to measure R.I of certain gemstones, the PRIM II is able to measure a wider range of R.I value from 1.000 to ~3.000, therefore covering the commonly known gemstones in the market and can also measure RI of diamonds, moissanites and other diamond simulants such as high zircon, strontium titanite, etc.

In addition, a fast and clean test can be easily done with the PRIM II, without the inconvenience and messiness of R.I liquid used in the traditional refractometer.

The PRIM II also comes with a downloadable software that provides a database of more than 50 gemstones with their various properties and possible origins, and a program that enables the user to enter known properties of the gemstone such as color, S.G. value, hardness, etc to ascertain what possible gemstone it is from the database information.


Inside Ring Engraving Machine – Mini (MPIREM)

A sturdy and reliable engraving machine, that is now a more portable size, providing ease of customization by engraving letters onto the inner surfaces of a ring.

The Presidium Inside Ring Engraving Machine – Mini, is a user-friendly engraving instrument that comes with an engraving diamond tip, a circular dial template, a complete set of operating instructions, a dust cover, and five brass sample rings.

The engraving machine is manufactured to the highest standards with hardened powder-coated paintwork.