Gemological study of heat-treated with flux ruby from Myanmar

Author: Nikoleta, Published:

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Tzankova N. 2016. Gemological study of heat-treated with flux ruby from Myanmar. – Geology and mineral resources, 1-2, 35-38 (in Bulgarian).

The paper provides data on identification peculiarities of the natural ruby from Mong Hsu (Myanmar) which after heat-treatment with a flux successfully resembles in color and clarity the high-quality crystals of Mogok deposit. The study is conducted with non-destructive methods in Gemological Laboratory at the University of Mining and Geology  “St. Ivan Rilski”. The studied sample is faceted, red with violet hue and most desired tone saturation – 80, specific gravity – 4.00, refractive index – 1,761-1,769. Highly fluorescents with red-violet light under a longwave UV lamp.  Throughout a 360° rotation under polariscope the stone blinks four times, light and dark with the exception of clearly visible portions that appeared light all the time. The spectrum of light absorption is slightly blurred. Pleochroism expressed in two different colors – violetish red and orange. Based on the established in the mineral inclusions of calcite, rutile, and fluorite, the crystal is defined as natural from Mong Hsu deposit in Myanmar. Smaller rutile crystals are partially dissolved and around them, secondary “fingerprint” inclusions are observed. Evidence of heat treatment with flux is established in the studied crystal – heavily damaged solid and fluid inclusions, rounded crystals, secondary “fingerprint” inclusions, elongated and curved gas tubes and gas bubbles, residual flux.  The main useful apparatus for detecting this kind of treatment – gemological microscope, polariscope, and spectroscopy.

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