Stone Info_Fancy Sapphire .pdf

***Fancy Sapphires*** LARGEST CONSUMERS : Padparadsa: Yellow & Orange Sapphire: fluctuates with changes in fashions, Natural yellows from Sri Lanka are often in demand, along with Australia, Montana, and Southeast Asia. Yellow sapphires are also highly coveted in Thailand, as this color is associate...

***Fancy Sapphires*** LARGEST CONSUMERS : Padparadsa: Yellow & Orange Sapphire: fluctuates with changes in fashions, Natural yellows from Sri Lanka are often in demand, along with Australia, Montana, and Southeast Asia. Yellow sapphires are also highly coveted in Thailand, as this color is associated with the country’s royalty and Thais also value golden sapphires Black: With black diamond in fashion, these sapphires have increased in popularity. In spite of this, the market for black sapphires remains comparatively small. MOHS SCALE: 9 VARIETY/ SPECIES/GROUP : Species-Corudum COLOR/HUE RANGE/VALUE: Padparadscha: yellowish orange to orangy red, with a whole range of tones intensely saturated combination of pink and orange hues without any noticeable brown coloring Pink Sapphire: red to purple in light tones with weak to vivid saturation Purple Sapphire: reddish purple to violetish purple in medium to dark tones with weak to vivid saturation. Yellow: greenish yellow to orangy yellow in light tones and all degrees of saturation. The finest yellow sapphire is yellow to orangy yellow, with medium tone and vivid saturation. Orange: yellowish orange to reddish orange in light to dark tones and all degrees of saturation. The finest orange sapphires are strongly red-orange with medium tone and vivid saturation. Green: blue-green through yellow-green, with light to very dark tone and usually low saturation, hue White/ Colorless: races of gray, yellow, brown, and blue are common and reduce the value. Black: fancy black sapphire is either black or a very dark blue that appears black under normal lighting Star Sapphire: colors from blue, black, gray, purple, or yellow, most expensive star corundum is semitransparent, with just enough silk to create a well-defined star, with strongly saturated bodycolor, blue star sapphire is vivid blue to violetish blue Color Change Sapphire: daylight-equivalent (fluorescent) light basic hue ranges from blue to violet, Under incandescent light the hue is violetish purple to strongly reddish purple, rare color-change sapphires change from green in daylight to reddish brown in incandescent light. CHEMICAL COMPOSTION: Padparadscha: Traces of iron and chromium, Pink Sapphire: trace elements chromium Purple Sapphire: varying combinations of iron, titanium, and chromium. Yellow & Orange: trace elements iron and possibly chromium, or from color centers, basaltic material Green: a mixture of two different color-causing mechanisms: yellow, caused by iron, and blue, caused by an iron and titanium intervalence charge transfer Color Change: trace element is vanadium FORMING SOURCE : basaltic deposits, Newer deposits are located in Africa and Vietnam, older sources Sri Lanka, Myanmar, Thailand, Australia, and the US state of Montana. CRYSTAL STRUCTURE: barrel- or spindle-shaped hexagonal pyramid or bipyramid POSSIBLE PHENOMENA: Asterism, Color-change Trapiche sapphire can resemble star sapphire but is not related to asterism, Its appearance is caused by strong bands of color that form along the crystal’s hexagonal growth zones. Trapiche sapphires are extremely rare. CLARIETY CHARACTERISTICS: Star Sapphire: tiny, needle-like inclusions rutile, usually made up of 2, 3, or 6 intersecting bands, resulting in 4, 6, or 12 rays. The most common stars have 6 rays, while 12-rayed stars are quite rare and include rutile and hematite inclusions, Hematite inclusions cause the asterism in black star sapphires. Green: color zoning the most common inclusions in fancy sapphire are silk (rutile needles), boehmite needles, included crystals, fingerprint inclusions, growth zoning, and color zoning. COMMON CUTS : ovals and rounds, but pears, marquises, emerald cuts, and antique cushion shapes are also available. Star Sapphire: cabochon star properly centered when the gem is upright TRADE NAMES : Padparadscha: means “lotus flower”, purple sapphires Purple Sapphire: “amethystine sapphires” ,“plum sapphire” and “rose sapphire.” Color Change: sometimes called "alexandrite-like sapphires", are much less expensive then actual alexandrite “star sapphire” encompasses all colors of star corundum except red, which is star ruby. “golden star” if a black star’s rays are golden or yellow COUNTRIES OF ORIGIN: Padparadscha: Sir Lanka is still considered the traditional source, the trade accepts padparadscha sapphires from many other locations, including Africa and Vietnam, the Umba River Valley in Tanzania Pink Sapphire: Highly saturated pinks,especially from Sri Lanka, Myanmar, and Madagascar—are rare, prized hues that sell quickly, Mozambique , the Umba River Valley in Tanzania,Vietnam, Montana, Hunza Valley and Kashmir areas of Pakistan, Jegdalek and Badakhshan in Afghanistan, Nepal, and Snezhnoe in Tajikistan, Greenland is also a future location Yellow and Orange: Sir Lanka, East Africa, Australia, Montana, and Southeast Asia, the Umba River Valley in Tanzania, Thailand* Green: Vietnam, Thailand, Montana, Australia Purple: Vietnam Black Stars: from Thailand and Australia Color Changing: Australia Blue Star: Thailand -Mogok has also been known as a source of some of the world’s finest star rubies and star sapphires. -Tsavo National Park in Kenya produce a variety of corundum colors. -Montana's Missouri River and Dry Cottonwood and Rock Creek areas, produce sapphires in a pastel color range COMMON TREATMENTS: Heat treatment and Beryllium lattice diffusion, artificial irradiation, glass filling MAIN SYNTHETIC PROCESS: flame fusion/Verneuil method, Some less common corundum synthesis methods are pulling, flux, floating zone, and hydrothermal. -flux method to create pink and orange fancy sapphires. -pulling process (also called the Czochralski method) to create red and orange corundum and star rubies. S Russia use pulling to make red, blue, and colorless corundum. Other Russian producers use the hydrothermal process to make a wide range of fancy sapphires, including color-change stones. - Union Carbide’s Linde Division synthesized the first flame-fusion star rubies and star sapphires in 1947. -Industrial Uses for Synthetic Sapphire: used in lasers , highly energy-efficient circuitry and LEDs and scratch-resistant display screens, fingerprint scanners, and touchscreens for smartphones. COMMON IMITATION MATERIAL: Glass is the most common fancy sapphire imitation material, doublets also mimic fancy sapphire and star corundum,Cubic zirconia (CZ), White/Colorless: preferred colorless sapphire over other diamond substitutes like synthetic cubic zirconia CUTTING/TRADE CETNER: ( No provide)