Sapphires crystallize in the trigonal crystal system forming elongate hexagonal prisms, but most naturally occurring sapphires may have modified often rounded shapes due to wearing by water as they are carried long distances by rivers and streams. Thus going by the clarity and distinctness of the “Gordon Star Sapphire” we may predict that the stone most probably originated either in Burma or Sri Lanka. However, sapphires originating in Africa, Thailand and some other countries do not have enough rutile, and the stars produced are not distinct. When the concentration of rutile is higher as in Burmese and Sri Lankan star sapphires, the stars produced are clear and distinct. The clarity and distinctness of the star depends on the concentration of rutile in the gemstone. The “Gordon Star Sapphire” originated either in Burma or Sri Lanka ? This phenomenon is known as asterism, which is responsible for the star effect produce by star sapphires. Thus the three stacks of rutile, will form three streaks of light intersecting one another at the center, forming a six-rayed star. The stacks are arranged in a three-fold pattern, each stack reflecting incoming light to form a single streak of light. The rutile fibers can exists as stacks or bundles of fibers.
Sometimes blue corundum can also contain another impurity called rutile, which imparts a milkiness to the stone known as silk. Greater the concentration of iron atoms in the crystal, stronger is the blue color produced. However if some aluminum atoms in the crystal structure are displaced by iron and titanium atoms, the corundum acquires a blue color. Sapphires belong to the group of minerals called corundum, which is a crystalline form of aluminum oxide. With the increase in the intensity of the blue color there is a corresponding decrease in its translucency and clarity.
The “Gordon Sapphire” is an emerald-cut blue sapphire with a more intense blue color than the “Gordon Star Sapphire” and weighing approximately 50 carats.
The weight of the stone is approximately 52 carats The color of the stone is a medium blue and the translucency and clarity of the stone quite good. The “Gordon Star Sapphire” is an oval cabochon-cut blue star sapphire, with a low dome and a distinct 6-rayed star centrally placed, with its rays extending to the periphery of the stone.
Characteristics of the gemstones The Gordon Star Sapphire
0 kommentar(er)
