GL Gem Raman
 System layout of the GL Gem Raman Download info sheet (PDF) |
 GL Gem Raman without case (13x13x3" or 33x33x7.6 cm optical board) |
The GL Gem RamanTM is an advanced gem testing instrument for gemmologists, gem dealers, mineral collectors and others; it is also an excellent educational tool. It complements the GL Gem SpectrometerTM and replaces other advanced spectrometer types such as NIR256-2.5 near-infrared spectrometers, FTIR (Fourier transform spectroscopy) spectrometers and temperature regulated Raman units.
The GL Gem Raman software allows real-time spectral acquisition; it can be used to operate both the GL Gem Spectrometer and the GL Gem Raman making them a powerful combo unit for advanced gemstone and mineral identification. The spectra can be saved and imported into a searchable database program with over 2,500 references; the database is linked to the large on-line mineralogical RUFF database for Raman spectra. GL Gem Raman users will also have access to the C.I.G. (Canadian Institute of Gemmology) gem reference library which is being compiled from the large C.I.G. gem study collection. Other reference databases can be consulted on-line.
 GL Gem Raman with Netbook |
 Sample Stage |
 GL Gem Raman with database |
Specifications:
Range: 200 – 2,600 cm-1 Resolution: ~3cm-1
Spot size: 10 – 15 micron at 20x magnification
Laser: confocal, 532nm regulated from 100mW to 300mW, Class 3B
Fully secured system with sampling stage covered by observation lid.
Size: 33 x 33 x 7.6 cm (13 x 13 x 3″)
Weight approximately 5 kg (11 lbs)
Power supply : 110 – 240 Volts (for laser) and USB connection to computer.
The GL Gem Raman will be offered in two versions
A basic OEM unit for expererienced users and a professional version for practising gemmologists, mineral collectors and others with added safety features and an expanded customized data-base.
1. The GL Gem Raman OEM is now available for clients who are familiar with the operation of the Raman unit and calibration procedures (must be conducted with safety goggles). The purchase price includes the GLGemRaman software (which also allows the operation of the GL Gem Spectrometer), the interface to search a database of over 2,500 references compiled and linked to the on-line RUFF database.
The export of a Raman spectrometer to certain countries may require an official safety certificate. Sales to EU countries as an OEM product is possible as the end user is responsible for safety issues; contact us for further information.
The price for the OEM unit FOB Vancouver, Canada will be under $ 7,000 for delivery by the end of March 2012. We will demonstrate the GL Gem Raman at the Euro Gem & Mineral Expo in Colmar, France (June 21 – 24, 2012) and other locations (TBA).
The shipping and import of the unit is the responsibility of the purchaser; please contact us for a special pre-order price.
2. The GL Gem Raman Professional is an ideal addition to the GL Gem Spectrometer which has close to 100 users around the world. The professional version will have self-calibrating features and can be operated without safety goggles. A 2 1/2 hour preparation workshop (TBA) to learn the operation of the Raman unit and calibration procedures is recommended; the purchaser will assume complete liability as to any consequences if the unit is not operated in compliance with instructions provided.
The GL Gem Raman users will also have access to an expanded data-base for gemstones which is under development. This professional version will be available in May 2012; the estimated price will be under $ 8,000.
The GL Gem Raman II with a TE cooled CCD and extended wavelength range (up to 3200cm-1) is under development and planned for release in the fall of 2012.
The GL Gem Raman is a powerful testing tool for gemmologists, mineralogists, jewellery appraisers and collectors.
Here a few comments about the advantages (and disadvantages) of a Raman over other advanced gem testing instruments such as FTIR, UV-VIS-NIR spectrometer, etc:
1. The GL Gem Raman is built to highest operator safety through fully enclosed and screened optics; see diagram for the optical design of the back-scattering geometry. To achieve highest signal strength no fiber optical connections are being used.
2. We have chosen a 300 mW 532nm laser as excitation source as commercial units are now available at economical prices. These devices use diode lasers to “pump” a Nd-YAG laser which operates at 1064 nm. The light from this laser is frequency-doubled to give green 532 nm light. This wavelength is about optimum for both Raman efficiency and the detector operating range. The Raman spectral range is from 200 – 2,500 cm-1 and output under 300 mW is usually sufficient and safe for the sample.
3. Raman CCD detectors have problems with fluorescence which in some cases “overwhelms” the signal; for example synthetic flame fusion rubies have very strong fluorescence. For those gem materials other testing instruments such as the GL Gem Spectrometer has to be used.
3. Raman spectroscopy is scattering-based, not transmission/reflection; i.e. no need for sample preparation. Only a small sample area is required; there are no movable optical parts and maintenance is minimal.
4. The GL Gem Raman has a sample compartment big enough to accommodate larger specimen and single pieces of jewellery.
The GL Gem Raman quickly can tell the difference between diamond, cubic zirconia, glass and zircon, distinguish jadeite from nephrite, separate real from faux pearls, tell whether it is ivory or plastic. There is great potential for detecting treatments (such as Opticon in emeralds) and colour enhancements in gemstones; it will help in the determination of the nature and colour origin of diamonds and other gemstones.
Information about Raman and databases
- Here a very good teaching module “Raman Spectroscopy” by the University of Cambridge.
- Read about an interesting project on Raman Spectroscopy and the Analysis of Gemstones.
- Jasinevicius, R. (2009) Characterization of vibrational and electronic features in the Raman spectra of gemstones (PDF) (MS thesis, unpublished).
- Large reference databases are available on-line such as at the RRUFF Project
- GIA Gem Project with over 200 gems from the Guebelin collection analyzed and Raman data recorded
 Raman spectrum recorded with the GLGemRaman |
 After importing the raw spectrum into CrystalSleuth and searching the RUFF database a match for jadeite was found. |
GL R&T together with GL Gem Raman users will build a reference database for the 532nm excitation laser used in the instrument.
Here a few samples of Raman spectra (click images to see more detail) obtained with the GL Gem Raman spectrometer; more spectra here.
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From RUFF Project |
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From RUFF Project |
Vancouver, B.C. – December 1, 2011
Wolf Kuehn, B.A., M.A., Dipl.oec, F.G.A., F.G.G. – GLR&T Project Manager
© 2011 Gemlab Research & Technology, Vancouver, Canada – www.gemlab.ws
The name and logo 
is a registered trade mark (Registration # TMA407372 Canadian Intellectual Property Office)