A new luminescent nondestructive method of analysis of solids has been developed in our Institute. It was described in detail in the article: Solomonov V.I., Mikhailov S.G., Shulgin B.V. et al. Dopant-sensitive luminescence spectroscopy of yttrium-aluminium garnet by high-current electron pulses. // Journal of Applied Physics, 1998 February 15, V.83, Issue 4, p. 2250-2255.

. . Method is very high sensitive to a content of point defects in material, especially to content of impurity d- and f- elements. Method allows to determine their concentration, valence, coordinating position in crystalline lattice and their chemical bond with each other and with others atoms. At present, the tabletop analyzer, based on the method has been developed. (Advertisement of this device below).

We hope, that the analysis method and equipment can be used more effectively for gems studying and solving of broad range gemmology problems. Such statement is based on, first, that method is nondestructive, second, that coloration of almost all gems is due to some extent the presence in them of impurity d-elements. The first results of using of the method in gemmology were reported in the article: Mikhailov S.G., Osipov V.V., Solomonov V.I. et al. A spectral-luminescent technique for gemmology.// J. of Gemmology, 1996, V.25, #4, p. 297-303. Possibilities of our luminescence method using for gemmology have not been not completely studied yet. We carried out investigations on collection of 15 samples-faceted alexandrites from Malyshevo occurance (Ural, Russia). (At present, this collection of alexandrites) is located in Moscow's Vernadskogo Museum, Russia). We can assert basing on the preliminary results that alexandrtites coloration and "alexandrite effect"; are not determined only by content of chromium impurity ions, and also by chromium ion distribution in different crystalline positions and their paired interaction among themselves. Under approximately equal total content of chromium and others impurities, crystals can be distributed at the least onto three groups associated with different value of "alexandrite effect";. We are sure that further investigations by our method of different quality alexandrites from Malyshevo occurance and other locations will lead to full understanding of such gems coloration nature. And on the base of this results will be possible to create instrument method of alexandrites quality estimation.

Similar problems may appear with others gems, for instance with emeralds. (We have possibility to receive different gems types for investigations.). As a result of investigations can appear new instrument methods of more precise gems quality determination.

Address: Vladimir I. Solomonov, Institute of Electrophysics UB RAS, 106, Amundsena st., 620016, Ekaterinburg, Russia. Phone: +7 3432 678779, fax: +7 3432 678794, e-mail: plasma@iep.uran.ru

Pulsed Cathodo-

Luminescence

Matter

Analyzer

Pulsed cathodoluminescence analyzer of matter (PCLAM-1) is based on new phenomenon – pulsed cathodoluminescence (PCL).

PCL is the result of nanosecond high current e-beam applying on specimen. PCL is exited in all dielectrics and semiconductors, glasses, ceramics and polymers. The PCL intensity is in a few thousand times greater than that one of traditional luminescence, that allows easy and exactly register spectra.

PCL spectra are characterized by the high stability and reproducibility of all parameters. PCL spectra have a characteristic feature both for mineral species as a whole and for concrete specimen.

PCL analysis need no preliminary treatment of specimen. It can be performed in air, at room temperature.

Pulsed cathodoluminescence matter analyzer is represented in a form of a compact tabletop device, that has no world analogues.

ADVANTAGES

· Broad range of applicability.

In is possible to analyze any dielectric or semiconductor.

· Rapidity of the measurements..

The time of spectrum measurement is a few seconds.

· High precision of the measurements.

This feature is determined by the opportunity of rapid accumulation of information for its statistical processing with a given accuracy.

· Non-destructivity of the method.

The input energy is lower than threshold of destruction.

· No need preliminary treatment of the analyzed specimen.

The method need no mechanical or chemical pre-treatment of a specimen or removing a gem from its frame.

· Low weight and small overall dimensions.

· Simple to operate.

· Ecological purity and safety.

· Economic electric power consumption.

APPLICATIONS

· MINERALOGY

Determination mineral species its typomorphism and purity.

· GEOLOGY

Search and determination of the quality of mineral raw materials.

· MINING INDUSTRY

Gem separation systems.

· PRODUCTION OF GLASS AND CRYSTALS

Determination of the quality of raw materials, intermediate and products.

· JEWELRY

Identification (species, natural or artificial) of gems and determination of their quality.

· CRIMINALISTICS

Identification of the authenticity of gems, the authorship of paintings, etc.

· SCIENCE

Study of the structure and composition of condensed matter.