Renishaw Raman
Renishaw Raman
The research-grade Raman platform that anchors major gemmological laboratories
Renishaw Raman refers to the line of research-grade confocal Raman microscopes manufactured by Renishaw plc of Wotton-under-Edge, Gloucestershire, and used as the principal Raman platform in major gemmological laboratories worldwide. The current inVia series — successor to the earlier RM1000 and 2000 platforms — combines a confocal Raman spectrometer with an optical microscope, giving the operator the ability to record Raman spectra from individual inclusions, growth zones, and surface features at the micrometre scale. For laboratory practice in coloured-stone identification, treatment determination, and synthetic-diamond screening, Renishaw inVia and a small group of comparable Horiba and WITec instruments are the working tools.
The Raman effect in gemmology
Raman spectroscopy records the inelastic scattering of laser light by molecular and crystal-lattice vibrations, producing a spectral fingerprint specific to the chemical bonds and crystal structure of the sample. Because the technique is non-destructive, requires no sample preparation, and can be performed through transparent host material, it is the natural method for in-situ identification of inclusions, for confirmation of species identity, and for the characterisation of structural features such as growth zoning, twinning, and treatment-related damage.
Capability and use
For gem identification, Renishaw inVia systems are used to confirm species identity from Raman spectra, to identify and characterise solid inclusions for origin determination, to detect synthetic indicators in HPHT and CVD diamonds, and to record characteristic peak shifts associated with treatment processes. Photoluminescence (PL) spectroscopy at low temperature, performed on the same platform with appropriate excitation, is the principal method for distinguishing natural from synthetic and treated diamonds, looking at NV, SiV, and related defect centres.
The systems support multiple excitation lasers — typically 488, 514, 532, 633, 785, and 830 nm — and the choice of wavelength is significant because fluorescence in many gem materials swamps Raman signal at shorter wavelengths. Operators commonly use 785 or 830 nm for stones with strong visible fluorescence (many emeralds, rubies, and treated stones) and shorter wavelengths for materials where higher signal strength is needed and fluorescence is manageable.
Laboratory deployment
GIA, Gübelin Gem Lab, SSEF, AGL, AGTA, and Lotus Gemology all operate Renishaw or comparable Horiba research-grade Raman systems for routine and specialist gem testing. The instruments are documented in laboratory practice articles in Gems & Gemology and in the technical notes published by the European laboratories. Both Renishaw and Horiba supply Raman systems specifically configured for gem laboratory use, with sample stages, gem-specific accessory holders, and software libraries containing reference spectra for the major species and varieties.
For inclusion analysis in origin determination — particularly the identification of trapiche-pattern minerals in emerald, rutile and zircon inclusions in sapphire, and the various solid phases that distinguish basalt-related from metamorphic ruby — the Raman platform is decisive. The technique resolves species identity in inclusions too small for traditional microprobe analysis and does so without destructive sample preparation.
Cost and accessibility
A current inVia configuration with multiple lasers and the standard accessory set falls in the £100,000 to £300,000 range, depending on options. The capital cost, the requirement for trained operators, and the floor-space and environmental requirements of a research Raman bench place these instruments outside routine retail trade use. Smaller fixed-wavelength Raman units are available from GemmoRaman, B&W Tek, and other manufacturers at a fraction of the cost; these handle routine species identification but lack the resolution and flexibility required for research-grade origin and treatment work.
In the trade
For dealers and retailers, the practical relevance of the Renishaw platform is that the major laboratories' coloured-stone reports increasingly depend on Raman and photoluminescence data alongside the traditional gemmological observations. When a Gübelin or SSEF report identifies a basaltic-suite ruby on the basis of inclusion analysis, the underlying data set typically includes Raman spectra recorded on a Renishaw or comparable platform. Understanding the role of the technique helps trade users read laboratory reports critically and identify the supporting analytical work behind a stated origin or treatment opinion.