Important Color-Change Sapphire


Sri Lanka A lovely, unenhanced color-change sapphire with excellent clarity, this "old world" stone exhibits a change of color when viewed under daylight or fluorescent vs. incandescent light. Its large size combined with the prestigious locality and high degree of clarity make this stone an excellent choice for the knowledgeable collector. Weighing approximately 27.19 carats and measuring 19.0 x 15.6 x 10.19mm
|Accompanied by a A.E. Thomas, South Africa, Gemstone report AT11376 stating that the natural sapphire is a color change blue-purple stone with typical Sri Lankan inclusions. Accompanied by a Gemological Institute of America report #1192148972 dated Feb 27, 2018 with notable letter stating that the 27.19 carats natural color change sapphire is blue changing to violet and that it originates from Sri Lanka. This stone exhibits a change of color when viewed under daylight or fluorescent vs. incandescent light. The GIA Notable letter states: This letter addresses the characteristics of the 27.19 carats oval mixed cut natural sapphire described on the GIA report 1192148972. The country of origin is Sri Lanka. The stone exhibits a change of color from blue when viewed under incandescent light. The trace element chemistry analysis indicates low concentrations of iron and titanium along with vanadium and chrome which are the primary color causing agents of change of color sapphires. Such a chemical profile is characteristic of sapphires from Sri Lanka. Sri Lanka is known for producing high quality sapphires in a variety of colors. A very important aspect of this sapphire is that it has not been subjected to heat treatment. This is evidenced by unaltered inclusions and its spectrospoic features. The intact inclusions are typical of untreated Sri Lankan sapphires. The most characteristic are negative crystals and exsolved rutile taking on the morphology of long needles. These needles, which have formed in an epitaxial pattern reminiscent of a very loosely woven cloth, are known as "silk". The color and physical properties of this sapphire are distinctive. Most sapphires are less than 10 carats, and stones over 25 carats, are quite rare. The large size, beautiful change of color, unheated nature and Sri Lankan origin make this a notable gemstone. Sincerely, GIA Laboratory