Natural vs. synthetic materials

In general Raman scattering creates a fingerprint spectrum of the bulk material under study. It does not tell whether it is natural or synthetic origin because their major chemical compositions and crystallography are often exactly the same. However, GemmoRaman-532™ is dual purpose spectrometer having also photoluminescence recording capabilities. Photoluminescence reactions are usually related to minor and trace elements in crystal lattice and in many specific cases gives very detailed information for separating synthetic gems from their natural counterparts and detecting various treatments.

Black materials

Raman spectrometer focuses very high intensity laser beam to the sample. Most gems and gemology related materials does not have problems since they are transparent for green light and will not absorb the energy. However, some black or very dark materials may absorb the light and heat up to temperatures where chemical decomposition starts. This may leave a small crater on the surface or if very unlucky shatter the sample. General rule is to be cautious especially for dark and/or organic looking materials.


Certain gems having high contents of chromium, manganese, uranium or REE (rare earth elements) fluoresces strongly in 532nm green light making Raman fingerprint measurement difficult or impossible. In many cases however, dual purpose GemmoRaman-532™ is capable to identify the material by it's fluorescence pattern. Additionally, photoluminescence reactions are practical for identifying many artificial treatments and with experience gives semi-quantitative estimate of trace elements such as chromium.

Composite stones

Classical example of rookie gemologist mistake is to make an identification based on R.I. measurement from the table of the gem. If one doesn't look more carefully by microscope or loupe it is really easy to miss the fact pavilion has been made of artificial product like glass while crown is natural gem. We guarantee this mistake works with Raman spectrometer too. Never fail to say hello to the stone by looking it carefully at microscope.


Many more pricey Raman instruments are coupled to microscope allowing more careful beam focusing for detecting inclusions in gems, they're called MicroRaman Confocal spectrometers. GemmoRaman-532™ is not designed for that purpose but for easy detection of bulk material. A good microscope alone would cost at least same amount of money than this product.


Artificial glass is group of amorphous solidified liquids having very vague set of broadened Raman fingerprints and photoluminescence reactions. There is literally thousands of different kind of glass compositions having diverse PL reactions due to color agents used. It is unpractical for trying to build complete reference database for glass substances.


Most metals are poor Raman scatterers. Some of them such as gold does not scatter at all. Raman spectrometer can not be used for identification of metals in jewelry. This fact has also pros: Gems can be studied without removing them from their setting because metals doesn't interfere with the Raman spectrum.