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Research Article |

Color Lightening Chemical Treatments for the Improvement of the Deep Red Colored Ruby Stones’ Quality

Corundum mineral species include rubies and sapphires. The mineral corundum is a natural gemstone mined from earth, and is colorless in its purest form. Variations of its color can be caused by trace elements that become part of the mineral crystal structure. Ruby is a crystalline form of aluminum oxide (Al2O3) in a closed packed hexagonal structure and is a well-known corundum. Ruby is pink-red to blood red colored gemstone, and its color arises from chromium impurities. The color is determined by three criteria, saturation, tone and hue. The price and quality of the rubies is determined by its clarity, color, size, with the color being the most important factor in determining its grade. The objective of this work is to increase the quality of the red ruby stones by reducing their deep red color after the chemical treatment of the ruby ores. The current treatment involves the usage of hydrofluoric acid, borax, and the heating of the ruby ores at temperatures that exceeded 1300°C. The lead glass treatment of the stones should involve the usage of a stronger lightening agent to minimize the lightening process time, the treatment should also involve the usage of a colorful and suitable metal oxide to increase the stones’ quality instead of the white borax, and the heating temperature of the stones should not exceed 900C to prevent the deepening of the color of the stones and to prevent the color from reverting to the original deep red color before the chemical lightening diffusion treatment.

Chemical Treatment, Red Rubies, Increase Stone Quality, Lead Glass Treatment, Stone Color Lightening

APA Style

Abdel-Wahab, H., Gund, T., Bozzelli, J. (2023). Color Lightening Chemical Treatments for the Improvement of the Deep Red Colored Ruby Stones’ Quality. American Journal of Chemical and Biochemical Engineering, 7(2), 20-23.

ACS Style

Abdel-Wahab, H.; Gund, T.; Bozzelli, J. Color Lightening Chemical Treatments for the Improvement of the Deep Red Colored Ruby Stones’ Quality. Am. J. Chem. Biochem. Eng. 2023, 7(2), 20-23. doi: 10.11648/j.ajcbe.20230702.12

AMA Style

Abdel-Wahab H, Gund T, Bozzelli J. Color Lightening Chemical Treatments for the Improvement of the Deep Red Colored Ruby Stones’ Quality. Am J Chem Biochem Eng. 2023;7(2):20-23. doi: 10.11648/j.ajcbe.20230702.12

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This article is an open access article distributed under the Creative Commons Attribution License ( which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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