The field of Gemmology with its gemmological examination methods is constantly evolving. Classical methods such as investigation with polariscope, refractometer and microscope will always be of particular importance in the characterization of gemstones and organic substances. More complex analyses such as recordings of spectra with spectrometers and chemical analyses were for a long time reserved for large gemmological laboratories.

In the last years, mobile spectrometers have become more widely accessible, which allows the practicing gemmologists to carry out a variety of additional examinations. It also expands the gemmologist's responsibility. The examination of a blue tourmaline, for example, no longer just involves determining the type of mineral; the identification of the variety is also of great importance. Whether a blue tourmaline is coloured by copper, and thus a Paraiba tourmaline, or by iron, and thus an indicolite, cannot be determined with traditional examination methods. However, measuring a simple absorption spectrum in the visible and near infrared spectral range provides the answer.

Schematic sketch of the measurement of a photoluminescence spectrum.

One of the biggest challenges currently is the identification of synthetic diamonds. Even though many “quick testing devices” have been developed and classical examination methods also enable a distinction, more advanced devices such as infrared and Raman spectrometers, as well as measuring of absorption and photoluminescence spectra, allow a much more precise characterization, including possible evidence of treatments.

There are numerous examples for a useful expansion of examination methods, from the detection of synthetic stones (e.g. diamonds, spinel etc.), to the differentiation of varieties (e.g. emerald vs. iron-coloured beryl, chrome tourmaline vs. verdelite etc.), to the identification of untreated cultured pearls or the detection of artificial fillers and dyes in opaque stones such as turquoise or lapis lazuli.

Basics of colorimetry.

The seminar “scientific methods in gemmology” addresses these modern examination methods and applies them in practice, with a focus on mobile devices in comparison to the stationary equipment in the gemmological laboratory. In addition to the practical application, a main goal is to train the understanding of the theoretical background of the respective methods, to discuss possibilities and limitations, learn to interpret the most useful spectra and get advice on how to build a well-founded database independently.

The following methods are discussed in detail:

• UV/Vis/NIR spectroscopy, as well as colour causes and colour measurement
• Photoluminescence spectroscopy
• Raman spectroscopy
• Infrared spectroscopy (FTIR)
• Chemical analysis

The next seminar in English language will take place from November 25^th to 29^th, the seminar fee is 750€.

If you are interested, This email address is being protected from spambots. You need JavaScript enabled to view it.!

• scientific gemmology
• advanced methods
• infrared spectroscopy
• Raman spectroscopy
• absorption spectrum
• spectroscopy

You want to extend your knowledge in gemmology?

You are looking for practical and feasible ways to add advanced methods to your gemmological laboratory?

Due to the steady progresses in technology in the last years, mobile and advanced instruments became more favourable and therefore more interesting for gemmologists. The supplementation of classical gemmological instruments with the modern techniques enables gemmologists to obtain a large amount of additional information regarding the authenticity and treatment of a gemstone. Furthermore, the identification of synthetic stones and imitations is also simplified.

To keep up with the constant progresses in this field, the German Gemmological Association offers a special seminar on scientific laboratory methods in gemmology.

The key topics are:

• • Raman spectroscopy
  • Photoluminescence spectroscopy
  • Infrared spectroscopy
  • UV/Vis/NIR-spectroscopy, as well as basics of colourimetry
  • Basic methods for chemical analysis

The seminar especially focuses on the use of mobile instruments. However, students will also receive insights into the work with stationary laboratory equipment. Some applications of modern techniques are:

• • Classification of diamonds, as well as identification of treated and synthetic diamonds
  • Identification of thermal enhancement of rubies, sapphires and red spinels
  • Identification of filler substances in emeralds, tourmalines, jadeite-jade, etc.
  • Identification of synthetic quartzes, synthetic spinels, synthetic alexandrites, etc.
  • Identification of colour causes of gemstones and differentiation of varieties (e.g. copper in Paraiba tourmaline, chromium in imperial topaz, etc.)
  • Identification of the colour authenticity of jadeite-jade, turquoise, cultured pearls, corals, etc.

The seminar fee is 750 €. More information and registration via email: This email address is being protected from spambots. You need JavaScript enabled to view it.

The next seminar will take place from 25.-29.11.2024.

• scientific gemmology
• advanced methods
• infrared spectroscopy
• Raman spectroscopy
• absorption spectrum
• spectroscopy