GL Gem Spectrometer™


GL Gem Spectrometer


We are proud to offer this economically priced and efficient portable spectrometer (UV-VIS-NIR, 300 – 1,000 nm) 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.

The GL Gem Spectrometer™is an innovative and advanced gem testing instrument for experienced gemmologists, gem merchants, mineral collectors and others; 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 capable to detect irradiated diamonds and possible HPHT treatments and whether green jadeite is naturally coloured. It replaces the traditional hand-held spectroscope avoiding potential eye damage under strong halogen light.

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 illumination.

There are GLGemSpec users in 32 countries around the world including: Australia, Austria, Belgium, Bolivia, Brazil, Canada, Czech Republic, Cyprus, Germany, France, Greece, Hong Kong, Hungary, Indonesia, Malaysia, Monaco, New Zealand, Philippines, Oman, Poland, Russia, Singapore, Slovakia, South Africa, Spain, Sri Lanka, Switzerland, Sweden, Thailand, UK, USA 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

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

Information Material

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

Jadeite Polymer Treated Jadeite Untreated

With a blue laser (405 nm) excitation source (GL Analyzer PL405/GL Xenon Flashlight Kit recommended) a strong luminescence band appears in the green wavelength range of polymer treated jadeite which is absent in untreated green jadeite.

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

Download jadeite info sheet (PDF, 540KB).

Gemlab R&T Development and Support Team

  • J Wolf Kuehn, B.A., M.A., PDP (SFU), Dipl.oec,  F.G.A., F.G.G. – GLR&T Project Manager, Vancouver, B.C., Canada
  • Stanislav O Konorov, Ph.D. (Laser Physics), Research Scientist, Michael Smith Laboratories (UBC), Vancouver, 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: 510 grams
  • Dimensions: 170 mm x 100 mm x 50 mm
  • Detector: Toshiba TCD1304DG linear array – Range: 200 – 1100 nm
  • Pixels: 3648 Pixel size: 8 um x 200 um
  • Signal-to-noise ratio: 300:1 A/D resolution:14 bit
  • NEW for 2015: diffraction order sorting filter for elimination of second order effects
  • Fiber optic connector: SMA 905 to 0.22 numerical aperture single-strand optical fiber
  • 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)
  • 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

We have fine-tuned the hardware and software of the GL Gem Spectrometer which has over 150 users world-wide; starting with the 2013 model we use a new sensor which will improve signal sensitivity.

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

Package includes:

  • GL Halogen 10 W Gem Holder
  • GL Fiber Probe and diffuser (optional)
  • USB Cable to connect to USB port of computer
  • 12/15 Volt power supply for light holder (110 – 240 V, includes international adaptor plugs) or battery power pack (optional)
  • software GLGemSpec (Version 2.7) with single user license
  • CD/USB stick with software and “How to Get Started” instructions
  • “Pragmatic Spectroscopy for Gemologists (2nd edition)” by Hanneman/Kuehn
  • access to data-base with over 350 reference spectra and 100 on-line image gallery

NEW LOW PRICE : US$ 1,495.00 

Please request pro forma invoice for shipping options outside North America. All wire transfers must follow FINTRAC Guidelines (will be provided in the pro forma invoice) or they will be rejected.


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

For work with larger samples and gems set in jewellery we recommend the GL Xenon Flashlight setup (see image) and/or the GL Fiber Probe with diffuser which can be purchased separately.

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 5/10W 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.

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
  • 12 – 15 V/1.5 A power adapter (110 – 240 Volts, international adapter plugs) or battery power pack (optional)

This light holder has been optimized for the VIS-NIR 400 – 950 nm range; with the additional diffuser adapter other light sources such as UV LED, Xenon flashlights, etc. can be used. 

GL Gem Halogen Holder

GL Gem Halogen Holder

The GL Halogen 5/10W Gem Holder is an exclusive design of Gemlab Research & Technology and is protected by copyright laws.

System Requirements

Portable GL Gem Spectrometer with 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 GLGemSpec program has a spectral colour bar for reference and a zoom feature with a fixed 400 – 700 nm range and user defined range.

Version 2.5 and up has a normalization feature built-in to allow for better comparison of user spectra; 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 recalibration 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 free firmware/CCD upgrades within 12 months if shipped to us at your cost and risk and we will return the unit to you at no cost. After 12 months a processing fee of $ 295 will be charged which covers the firmware update with any CCD upgrade (can be customized), re-alignment and recalibration, etc. and return shipping charges; other repair services upon request. Software updates are always free.

Transmission Spectra (non-polarized) 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

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 410 nm is due to limitations of the halogen light bulb.We improved readability in the 400 nm and below as well as above 900 nm 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. A multi-bandpass detector coating might be required to eliminate second-order effects. See below.

Transmission spectrum of synth.ruby (Verneuil)

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 Irradiated diamonds with typical 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

Emission spectrum of UV LED 365 nm (Nichia, black), LED 395 nm (blue), IR LED 835 nm (red) – Synth.flame fusion ruby, scope mode with emission peaks, excitation source UV LED 395 nm (edited in Spekwin32). Second-order effects from diffraction at 750 and 800 nm. 

NEW for 2015 models: diffraction order sorting filter for elimination of second order effects included

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.

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

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.A., F.G.G. – GLR&T Project Manager

© 2010 Gemlab Research & Technology, Vancouver, Canada –