FLAWLESS GISA CERTIFIED LARGE 3.7CT BLUE SAPPHIRE WITH LOVELY RECTANGULAR CUSHION CUT FROM CEYLON (SRI LANKA) THERMAL TESTED HIGH!

THIS IS A NEAR FLAWLESS GEM AND A LUCKY BUYER MIGHT JUST HIT THE JACKPOT ON THIS ONE! ONE OF THE LAST LARGE BLUE SDAPPHIRES I HAVE. THIS GEMSTONE IS A LOVELY 3.70CT (0.74G PLEASE SEE PHOTO MULTIPLY WEIGHT BY 5 TO GET CARATS) BLUE SAPPHIRE GEMSTONE WITH A BEAUTIFUL RECTANGULAR CUSHION CUT. COMES WITH A SMALL PERSPEX PRESENTATION CASE AND SUPPLIED GISA CERTIFICATE.
 
THIS PARTICULAR STONE WAS BOUGHT IN 2011 FROM A SELLER IN CHANTHABURI THAILAND WITH THE ORIGEN OF THE STONE INDICATED AS CEYLON (SRI LANKA). IT HAS A VVS (EYE CLEAR) CLARITY WHICH MEANS IT IS FREE OF INCLUSIONS AS SEEN WITH THE NAKED EYE WHICH IT APPEARS TO BE. IT WAS ALSO SOLD AS A HEAT TREATED BLUE SAPPHIRE GEMSTONE.
 
TESTS PERFORMED:
PASSED THE SCRATCH TEST: IT DID SCRATCH A GLASS WINDOW PANE WHICH WOULD INDICATE IT IS HARDER THAN GLASS. (MOHS HARDNESS GLASS 5.5-6.5 SAPPHIRE 9.0)
PASSED THE ELECTRON UV LIGHT EMISSION TEST: NO UV REACTION.
NATURAL BLUE SAPPHIRES USUALLY SHOW NO UV AFFECT DUE TO SOME IRON TRACE ELEMENTS BUT SOME NATURAL BLUE SAPPHIRES LIKE THE CEYLON BLUES CAN SHOW A ORANGE TO RED FLUORESCENCE. A SYNTHETIC BLUE SAPPHIRE USUALLY SHOWS A WEAK TO MODERATE CHALKY BLUE TO YELLOWISH GREEN FLUORESCENCE.
(THE UV LIGHT HIT THE ELECTRONS. THEY JUMP AND FALL BACK. THEY RADIATE LIGHT OF A CERTAIN WAVELENGTH WHEN THEY DO WHICH IS SPECIFIC TO EACH ELEMENT IN THE MINERAL. THIS IS CALLED FLUORESCENCE. ONLY 10% OF GEMSTONES EXHIBIT A FLUORESCENCE AFFECT LIKE RUBIES, SAPPHIRE, TOPAZ, OPALS AND DIAMONDS. GLASS AND ALL NATURAL QUARTZ VARIETIES DOES NOT SHOW A UV AFFECT.)
PASSED THE THERMAL CONDUCTIVITY TEST: TESTED THE THERMAL CONDUCTIVITY WITH A MIZAR PRESTIGE SERIES 2 DIAMOND TESTER. IT MOVED UP THE LADDER FROM STANDARD LEVEL 3 TO LEVEL 6. FOR SAPPHIRES AND RUBIES A LEVEL OF 6 TO 7 IS THE NORM FOR THIS TESTER.
(WITH THIS TESTER GLASS MAKES NO MOVEMENT AND QUARTZ GOES UP TO LEVEL 4.)
 
SIZE: 9.6mm x 7.0mm x 5.2mm
 
THIS SAPPHIRE GEMSTONE HAS A SUPPLIED GISA (GEMMOLOGY INSTITUTE OF SOUTHERN AFRICA) CERTIFICATE. THIS COMPANY COULD NOT BE CONTACTED BY CONTACT DETAILS SUPPLIED ON THE BACK. THERE IS NO WEBSITE TO CHECK PAST REPORTS THAT I COULD FIND. I DO NOT KNOW IF STILL IN EXISTENCE. TO THEIR CREDIT THOUGH I HAVE SEEN CERTIFICATES BY THEM THAT I COULD INDEPENDENTLY VERIFY AS CORRECT.
 
MY PERSONAL CONCLUSION REGARDING THIS GEMSTONE:
A LARGE GEMSTONE IN NEAR FLAWLESS CONDITION. THE COLOUR IS A STRONG DARK ROYAL BLUE. THE COLOR AND CLARITY OF RUBIES AND SAPPHIRES IS ALSO COMMONLY ENHANCED BY HEAT TREATMENT. IT WAS STATED THAT OUR GEMSTONE WAS HEAT TREATED.
THE EASIEST WAY TO TELL BETWEEN A NATURAL AND LAB-CREATED SAPPHIRE IS THE FLAWLESSNESS. OUR STONE HOWEVER HAS A VVS CLARITY AND IS EYE CLEAR OF INCLUSIONS ALTHOUGH IT MIGHT SHOW INCLUSIONS UNDER MICROSCOPE.
NATURAL BLUE SAPPHIRES USUALLY SHOW NO UV AFFECT DUE TO SOME IRON TRACE ELEMENTS. OUR GEMSTONE ALSO SHOWED AN INERT OR NO UV REACTION.
MY CONCLUSION:  IT IS PROPABLY A SYNTHETIC SAPPHIRE GEMSTONE BUT A LUCKY BUYER MIGHT JUST HIT THE JACKPOT ON THIS ONE
 
DISCLAIMER: THIS GEMSTONES BELONGED TO A FAMILY MEMBER THAT HAS PASSED AWAY. HE COLLECTED GEMSTONES DURING THE EARLY TWENTY FIRST CENTURY MANY WERE BOUGHT ON EBAY AND OTHERS BY TRAVELLING TO OTHER COUNTRIES. I AM NO GEMSTONE EXPERT AND COULD ONLY PERFORM SOME PRELIMINARY TESTS - ADVANCED INTRUMENTS ARE NEEDED TO DISTINGUISH ONE GEMSTONE FROM ANOTHER AND TO CONFIRM IF IT IS NATURAL OR LAB MADE.
 
SAPPHIRE:
Sapphire is one of the four precious gemstones amongst Rubies, Diamond and Emerald. Sapphire rank 9 on the Mohs scale of Hardness. Only a diamond can scratch sapphire.
Sapphire is a all the colours of the corundum mineral except red, which is the color of the ruby. Corundum is relatively common in nature, and is completely colourless. Small amounts of metallic elements such as Cr, Fe and Ti can substitute for aluminum in the structure, which gives rise to many colour variations in sapphire.
Historically production of sapphire has been from Myanmar (Burma), Thailand, India and Sri Lanka (Ceylon). More recent important sources include East African countries of Madagascar, Tanzania and Mozambique.
Synthetic sapphire has been produced commercially since 1902. Lab-created sapphires come from synthetic forms of corundum, used to make synthetic sapphires, and rubies (the other precious gem made from corundum). Lab-created gems are essentially the same as their natural counterpart, with the same visual qualities and hardness. 

PLEASE ALSO SEE MY OTHER ITEMS LISTED. I HAVE VARIOUS OTHER GEMSTONES ALSO ON AUCTION THIS WEEK. COPY THE URL UNDERNEATH AND PASTE INTO GOOGLE AND IT WILL TAKE YOU DIRECTLY TO ALL MY LISTINGS THIS WEEK.
https://www.bidorbuy.co.za/seller/3685641/ErnRex1545