GL Gem Spectrometer™



GL Gem Spectrometer

The GL Gem Spectrometer™ 2018 model with new motherboard and “Point & Shoot” software. Now with integrated fast search spectral library of over 250 gem references covering common Gemstones, Diamonds (incl. treatments) and PL405 spectra.


We are proud to offer this economically priced and efficient portable spectrometer (UV-VIS-NIR, 300 – 1,000 nm, PL Spectroscopy) which can be operated from the USB port of a laptop computer. No additional drivers are necessary; the easy to learn GLGemSpec software displays both absorbance and transmittance spectra in real-time.

The best-selling GL Gem Spectrometer™is an innovative and advanced gem testing instrument for gem dealers, mineral collectors, gemmologist appraisers and geoscience applications; it is also an excellent educational tool.

It helps to identify gemstones based on their spectral pattern and to analyze chromophores causing certain colours. It is probably the most important low cost diamond testing tool as it is capable to detect the Cape lines (98% of  natural diamonds are Type Ia), the GR-1 band of irradiated diamonds, the Si center often seen in CVD grown diamonds (in some cases without LN cooling), possible HPHT treatments, whether green jadeite is naturally coloured or spinel is synthetic or heat treated and much more.

The unique gem light holder is mounted directly onto the spectrometer allowing fast real-time spectral analysis and bulk testing of both rough and faceted gemstones. It also has a built-in diffraction order sorting filter for elimination of second order effects when used with UV and laser excitation (PL spectroscopy). The GL Gem Spectrometer replaces the traditional hand-held spectroscope avoiding potential eye damage under strong halogen light.

There are GLGemSpec users in over 35 countries around the world including: Australia, Austria, Belgium, Bolivia, Brazil, Canada, Czech Republic, Cyprus, Germany, France, Greece, Hong Kong, Hungary, Indonesia, Italy, Malaysia, Monaco, New Zealand, Philippines, Oman, Poland, Russia, Singapore, Slovakia, South Africa, Spain, Sri Lanka, Switzerland, Sweden, Taiwan, Thailand, UK, USA, Vanuatu and Vietnam.

I utilize my GLGemSpec to assist me in identifying and verifying gemstones from suppliers. The accuracy is better than the human eye in observing the spectral data. When there is something that does not appear as expected during testing I scrutinize the data more closely. Having the advantage of covering a large spectrum the GLGemSpec allows me to process more data about the products prior to sale or resale and assists in keeping records of those items.

R. Kreinbrink, Owner, SOC Jewelry

I love my GL GemSpectrometer! It’s really quite simple to use, and it’s a fantastic help in my research in gem magnetism. Not just a tool for gem identification, I can use the spectrometer to identify specific metals that can cause gem color and magnetism. For example, with the spectrometer I can quickly and easily determine if a tourmaline is colored blue by copper, establishing whether or not it is a true Paraiba-type tourmaline.

For my research, its important to know definitively which metals are causing color and magnetic response: is chromium causing red color in a particular gem, or is the red color due to iron?; is a strong magnetic response in a yellow gem due to iron or to manganese?; is a weak magnetic response in an orange gem due to the presence of chromium rather than iron?

With the GL Gem Spectrometer, I can answer these questions myself without the need to send specimens off for costly lab tests. I can also save all my results on my computer for future reference, allowing me to establish a database of spectra for different gems and different metals.

Kirk Feral, San Diego, CA

Please note: this is an advanced spectrometer which must be operated by a qualified gemmologist and/or spectroscopist.

Click here to order the GL Gem Spectrometer (ORDER ONLINE). Click here to download Promotional Flyer   (PDF)

For proper identification of CVD grown diamonds we recommend the use of the GL Gem Spectrometer to detect any “Cape lines”(98% of  natural diamonds are Type Ia). If not present inspect under microscope with crossed polarizer, download article here (PDF) or for more instructions from here (PDF). 

Typical “Cape” lines in natural diamond (external GL Xenon flashlight used)

GR1 band as seen in irradiated diamonds (external GL Xenon flashlight used)

Jadeite Untreated Jadeite Treated Cobalt doped glass  filled Sapphire

The GL Gem Spectrometer™ is very efficient in detecting whether green jadeite has been treated or not or whether the blue stone is one of the newer glass filled sapphires.

Detection of polymer treated jadeite

Detection of polymer treated jadeite (external GL Xenon flashlight used)

Jadeite Polymer Treated Jadeite Untreated

Using PL spectroscopy with a blue laser (405 nm) excitation source (we recommend the GL Analyzer PL405 Kit) a strong luminescence band appears in the green wavelength range of polymer treated jadeite which is absent in untreated green jadeite. Download jadeite info sheet (PDF, 540KB).

For your own protection always use laser safety goggles when operating any type of laser equipment.

Information Material

Gemlab R&T Development and Support Team

  • J Wolf Kuehn, B.A., M.A., PDP (SFU), Dipl.oec,  F.G.G. – GLR&T Project Manager, Vancouver, B.C., Canada
  • Stanislav O Konorov, Ph.D. (Laser Physics), Senior Scientific Assistant, Dept. of Chemistry, University of Victoria, B.C., Canada
  • Matthew Stockinger, B.A. (Chemistry, Mathematics), M.S. (Teaching), St. Cloud, MN, USA
  • W. William Hanneman, Ph.D. (Chemistry, retired), Rio Rancho, New Mexico, USA

Fraunhofer spectral line position observed with GL Gem Spectrometer vs known position (10 solar spectra)


Specifications of the GL Gem Spectrometer™

  • Weight: 520 grams
  • Dimensions: 170 mm x 84 mm x 59 mm
  • Detector: Toshiba TCD1304DG linear array – Pixels: 3648 Pixel size: 8 um x 200 um
  • Range: 300 – 1000 nm (optimized for VIS-NIR 400 – 950 nm range)
  • Signal-to-noise ratio improved: 500:1, 16 bit A/D resolution; fast onboard averaging
  • Diffraction order sorting filter for elimination of second order effects (PL spectroscopy)
  • NEW for 2017: upgrade-able motherboard with “Point & Shoot” software version 3.x and integrated spectral library of over 250 gem references of Gemstones, Diamonds and PL405 spectra (experimental).
  • Wavelength and Optical resolution: 300-1000 nm < 1 nm
  • Exposure time: 2.5 ms-10 s CCD reading time: 14 ms Data transfer speed: 200 ms / 100 ms (2 points binding)
  • Fiber optic connector: SMA 905 to 0.22 numerical aperture single-strand optical fiber
  • Power consumption: 200mA @ 5V from computer interface: USB 2.0, HID 2.0 (USB cable included)
  • Operational system: Windows XP/Vista/Windows 7/8/10 32/64 bit and others; with proprietary firmware for GL Halogen 10W Gem Holder

Integrated fast search spectral library

The GL Gem Spectrometer is an exclusive design by Gemlab Research & Technology (a subsidiary of Canadian Institute of Gemmology) and its software is protected by copyright laws; we are the exclusive distributors worldwide.

We rent spectrometers per week/month; please contact us at for more details.

Portable GL Gem Spectrometer™ System with GL Halogen 10W Gem Holder (included)

Package includes:

  • GL Gem Spectrometer model 2017/18 (new motherboard, upgrade-able)
  • GL Halogen 10 W Gem Holder (new modified design with extra SMA 905 port)
  • USB Cable to connect to USB port of computer
  • 12/15 Volt power supply for light holder (110 – 240 V, international adaptors)
  • CD/USB stick with “point & shoot” software (version 3.x)  and “How to Get Started” instructions
  • “Pragmatic Spectroscopy for Gemologists” (2nd edition, 64 pages) by Hanneman/Kuehn
  •  software integrated spectral library of over 250 gem references (Gemstones, Diamonds and PL405 spectra)
  • access to data-base with over 350 reference spectra and 100 on-line image gallery

PRICE US$ 1,795.00 FOB Vancouver, B.C., CANADA

Gemlab Research & Technology is manufacturer and exclusive distributor worldwide; we do not use re-sellers.


Step-by-Step Instructions for the Beginner

Setup for external illumination of sample with GL Xenon Flashlight

Setup for external illumination of sample with the GL Xenon Flashlight


Shine the GL Xenon Flashlight from above onto the sample and observe the spectral graph

Completely portable system with Tablet and battery pack

Completely portable system with tablet and battery pack

For work with darker gems and diamonds, larger samples and/or gems set in jewellery we recommend the GL Xenon Flashlight setup (see image). 

For photo-luminescence studies (PL spectroscopy) we recommend the GL Analyzer PL405 Kit which provides a blue laser (405 nm) and necessary accessories.

Using a fiber probe with the GL Gem Spectrometer requires a customized setup with external lighting and will change several parameters for obtaining a spectrum. Results may vary dependent on light source and its position, sample size (affecting path length) and orientation, etc.; spectra will look different from those found in the database and/or obtained with the GL 10W Halogen Gem Holder.

Click here to order the GL Gem Spectrometer

Specifications of the GL Halogen Gem Holder

GL Halogen 10W Gem Holder with built-in cosine corrector, 20 x 20 mm opening and cooling fan. Similar to an integration sphere the built-in halogen light source is internally diffused by the holder’s black matte finish. The 2017 model has an extra SMA 905 port which allows use of fiber optics testing probe.

This unit is included in the basic GL Gem Spectrometer™ package.

  • Weight: 80 gr
  • Dimensions: 75 x 50 x 27 mm
  • Size of opening: 20 x 20 mm
  • NEW for 2017: SMA 905 port for use as an external light source and non-solarizing fiber optics probe.
  • 15 V/1.5 A power adapter (110 – 240 Volts, international adapters) or battery power pack (optional)

This light holder has been optimized for the VIS-NIR 400 – 1000 nm range, however, there may be considerable noise below 400 nm.


GL Gem Halogen Holder

GL Gem Halogen Holder

Assembly with non-solarizing GL Reflection Probe (optional) for use with UV light sources (UVNS) etc.

Other light sources such as UV LED, Laser excitation, Deuterium lamp, Xenon flashlights, etc. can be used as shown above; a fiber probe will change optical parameters and resulting spectra may look different from those obtained in transmission mode.

The GL Halogen 10W Gem Holder is an exclusive design of Gemlab Research & Technology and is protected by copyright laws.

System Requirements

GL Gem Spectrometer with Dell Mini Netbook

The GL Gem Spectrometer™ requires a computer with a USB port (no separate drivers necessary, USB 2.0/HID 1.0 compliant).

The software package contains the GLGemSpec program (Windows XP/Vista/Win 7/8/10 for 32/64 bit); for developers the VIs and a runtime package for LabVIEW 2009 are included. A single user license is provided for each GL Gem Spectrometer system.

The new “point & shoot” GLGemSpec program (version 3.x) allows direct printing/saving (as image, reference spectrum, etc), automatic normalization in transmission and absorption mode; it has a spectral colour bar for reference and a zoom feature with a fixed range ( default 360 – 950 nm) and user defined range (from 300 – 1,000 nm).

The software works only with the modified firmware of the GL Gem Spectrometer.

Users of the GLGemSpec system have access to the Gemlab R & T spectra database which is available on-line.

Our Warranty and Commitment

The GL Gem Spectrometer is an advanced gem testing instrument for users who have a good understanding of spectroscopy and should be familiar with the use of a traditional gemmological spectroscope and the interpretation of spectra. The instrument is not capable of identifying or naming a sample; it should be used with other gem testing tools before arriving at a conclusion.

If you are not satisfied with the performance of the spectrometer we will accept returns within 10 days but have to charge a restocking fee of 10% to cover our expenses of shipping/handling and re-calibration if necessary. The purchaser is also responsible for the shipping and insurance to return the item.

We will repair and replace your GL Gem Spectrometer if necessary due to defective parts, etc during the first 6 months unless other consumer protection regulations exist in your country.

We also offer firmware/CCD upgrades for a processing fee of US$ 530 which covers the update, new software, re-alignment and re-calibration, etc. and return shipping charges; other repair services upon request. Software updates are always free.

Transmission Spectra (non-polarized and not normalized) obtained with the GLGemSpec

Flame Fusion Ruby TR Sapphire BL Pailin CZ Pink TR
Synth. flame fusion ruby Unheated blGR Pailin sapphire Pink cubic zirconia (not normalized)

Note: Transmission dips correspond to dark lines or bands seen in a hand-held spectroscope

Converted and Normalized Absorption Spectra

Flame Fusion Ruby ABS Sapphire BL PailinABS CZ Pink ABS
Synth. flame fusion ruby Unheated blGR Pailin sapphire Pink cubic zirconia

Corrected transmission spectrum of synth. flame fusion ruby

The non-polarized spectrum of flame fusion ruby in the graph below shows corresponding absorption lines and bands as would be seen in a diffraction grating hand-spectroscope.

Corrected transmittance spectrum (non-polarized) of synth. flame fusion ruby as seen in the GLGemSpec interface: For example if transmission for certain wavelengths (in nm) is LOW absorbance for those wavelengths will be HIGH (in a conventional spectroscope one would see dark lines or bands at these positions; indicated as bars and lines).

Noise visible below 350 nm is due to limitations of the halogen light bulb.We improved readability in the 400 nm to 1000 nm range by using a higher voltage (15V) to drive the halogen bulb.

For experiments LW and SW UV LEDs can be used to illuminate samples in the light holder.

Transmission spectrum of synth. ruby (Verneuil)

For more sample spectra go here or download selected absorption and PL 405 spectra (PDF).

Tourmaline, CU bearing JadeiteBurUntreaA
Typical absorption in the 920 – 940 nm range of copper bearing tourmaline (edited in Spekwin32) Jadeite, Burma – naturally coloured with typical absorption lines at 437 nm, 630 nm, 655 nm and 690 nm (edited in Spekwin32)
Dia10CapeA DiaBlGrIrrA
Typical 415.5 and 478 nm peaks for Cape type Ia diamond Known irradiated diamonds with GR-1 band at 741 nm
Diamond, Blue Diamond, BrRed Diamond, Yellow

Colour-producing diamond defects not related to diamond type can be seen with the spectrometer (see peaks at 480, 550, 575, 595, 741 nm) – edited in Spekwin32

Pink Diamond

Pink Diamond, HPHT treated, irradiated (405 nm laser excitation, room temperature)

Emission spectrum of synth. flame fusion ruby: UV LED 365 nm (Nichia, black), LED 395 nm (blue), IR LED 835 nm (red) (edited in Spekwin32).

Second-order effects from diffraction at 750 and 800 nm (in pre-2014 models).


Download the archived GLGemSpec files “RubySynFlame.fak and Reference.fak” (.rar file), and import for smoothing, normalization, base-line correction, zoom, editing into Spekwin32 ( Download Spekwin32 revised version from Nov 05 2012, file size: 1.3 MB by F. Menges).

About This Project

The GL Gem Spectrometer™ system has been under development for several years. My interest in spectroscopy goes back to Bill Hannemann’s book “Video-Spectroscopy: 21st Century Gemology” published in 1988. With 2 years of university physics in my academic background I was intrigued by Bill’s concept and saw its potential but Video Spectroscopy never took off the ground.

Almost 20 years later I started using an Ocean Optics USB 2000 (200 – 850 nm) spectrometer for research in the UV range and a NIR 256-2.5 spectrometer for IR studies – but I must admit that the GL Gem Spectrometer has replaced both; it is being used every day in the Gemlab Research & Technology lab and during courses I teach at the Canadian Institute of Gemmology (C.I.G.).

The maker of the spectrometer is a post-doctoral research scientist working at a local university lab facility; he is internationally acclaimed for his work and long list of publications about transmission and Raman spectroscopy (in particular its application in stem cell research).

I would like to thank Dr. Bill Hanneman for including the GL Gem Spectrometer in his book “Pragmatic Spectroscopy for Gemologists” with many reference spectra obtained from his own collection of gems; a copy of the 2nd edition is included with the purchase of each GLGemSpec system.

Read:  ISG: The Future of Raman Spectroscopy (2014).

The GL Gem SpectrometerTM can be used in LabVIEW environment; VIs provided for developers.

Spectrograph provided by John Harris, Gemlab.UK

GL Halogen Holder and External Xenon Light Source

GL Halogen Holder and External Xenon Light Source

New version of Spekwin32 will display absorption spectrum  as seen through a hand spectroscope.

New version of Spekwin32 will display absorption spectrum as seen through a hand spectroscope.



Wolf Kuehn, B.A., M.A., Dipl.oec, F.G.G. – GLR&T Project Manager

© 2017 Gemlab Research & Technology, Vancouver, Canada –