How To Identify Beryllium Treated Corundum

This treatment is performed using a combination of high temperatures (1700 degrees +/-) and possibly the use of high pressures. The main characteristic of this treatment is the use of additives like beryllium (chrysoberyl powder or other industrial compounds), which cannot be proven using standard gemological techniques. The stones are carefully studied before treatment.

The application of sophisticated techniques to identify beryllium treated stones has added more problems. EDXRF (Energy dispersion X-ray fluorescence spectrometry) may have difficulty detecting beryllium treated stones. WDXRF (Wavelength Dispersion X-ray Fluorescence spectrometry), on the other hand, may be able to detect Be (beryllium). Mass spectroscopy (Secondary Ion Mass Spectroscopy and Laser Ablation Inductive Coupled Plasma Mass Spectroscopy) seems to be the alternative. But they are too costly for standard laboratory use.

Gemological characteristics of beryllium treated corundum

- General features
The gemstones are usually very bright colored with excellent luster. The colors vary from red, orange red, orange, pink orange, pink, yellow, purple, purplish violet and blue. Most beryllium treated rubies when placed table down on a white background may show yellow to orange color concentration near the girdle.

- Magnification
Ruby (dark to brownish to purplish red corundum from Songea, Tanzania):
All iron rich rubies from Thailand, Madagascar, Songea (Tanzania) may be suitable for beryllium treatment. Most Songea (Tanzania) specimens are very clean but may show typical blue circular patches or hexagonal pattern radiating from included crystals. Sapphire (greenish blue or greenish yellow from Australia and Sri Lanka, East Africa): The sapphires may display unusually strong color banding near the center. The Madagascar sapphires (pink, yellow, blue, colorless etc.,) may show glassy or cottony spherical pattern surrounded by spotted circular fingerprints.

Note: Sapphires from Songea, Tanzania and Sri Lanka may show similar internal features.

- Polariscope or cross polar with magnification
Beryllium treated stones may show strain pattern. Indication only.

- Fluorescence
Some stones may show strong but patchy yellow or orange fluorescence under long wave UV. Some stones may even display chalky blue reaction.

- Immersion techniques
The presence of typical uneven color concentration, colorless rim with small orange colored halo, and color bleeding from cracks are indications of new treatment.

Note: The colors of treated stones may not be 100% stable. Some stones may have been possibly irradiated after heat treatment for enhancement purposes.