![]() The conditions for heat treatment vary, depending upon the individual May require such long times that it is impractical) Of ruby) to more evenly distribute through the crystal. ![]() Of color) because heat allows the color-causing impurity (Cr, in the case ![]() Heat treatment may also remove local color concentrations (remove patches The inclusions may also improve the clarity of the stone. Inclusions cause some stones to look cloudy, heat treatment that dissolves Ti from rutile inclusions) into the surrounding corundum. Heat causes dissolution of inclusions and diffusion of impurites (especially In some cases, heat treatment will improve the depth of color because Via charge transfer (see lecture on colorĬonversely, stones that are too deeply blue may be lightened by oxidation Fe++ causes color in a variety of sapphires An especially important example involves reduction of Fe In some cases, heating the stone causes changes in the oxidation state Heat treatment may change the color of corundum for a variety of reasons. Heat Treatment of Corundum Heat treatment of gemstones to is done to improve their appearance. Synthetic corundum may contain a visible seed crystal (esp. The presence of flux inclusions and non-natural gas inclusions Natural origin may be proved by inclusions (e.g., natural gaseousĪnd fluid bubbles) and spectroscopic measurements.How do I tell if the stone is synthetic? Synthetic rubies appeared on the market in 1908. It is possible to synthesize both clear crystals and stars. Star can change positions depending on where the light hits That the chemical formula of rutile is TiO2, and Ti is one of the elements These are parallel to hexagonal faces and thus at 60 degrees. ![]() NOTE: There are 3 special orientations in which rutile crystals occur. (absorbs blue, transmits and fluoresces red) Red (ruby is Latin for red), may also be pinkish or brownish-red Is more simply considered a subdivision of the hexagonal crystal system. *Note: some texts list the crystal system of ruby as trigonal.
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