STAR SAPPHIRE FROM THAILAND WITH GISA CERTIFICATE TESTED HIGH LEVEL 6 THERMAL CONDUCTIVITY!

THE ONLY STAR SAPPHIRE WE HAVE. THIS GEMSTONE IS A 19,19CT (3,84G PLEASE SEE PHOTO MULTIPLY WEIGHT BY 5 TO GET CARATS) STAR OVAL CABOCHON SAPPHIRE GEMSTONE. COMES WITH A SUPPLIED GISA CERTIFICATE.
 
NOTE THIS WEEK I HAVE 3 OTHER SAPPHIRES ON AUCTION. BESIDES THIS STARRY BEAUTY I HAVE ORANGE, BLUE AND GREEN SAPPHIRE GEMSTONES ALSO ON AUCTION. ALL MY AUCTIONS END AT 22H30 SO IT IS ADVISABLE TO PUT IN AN AUTOMATIC BID (HIGHEST PRICE YOU ARE WILLING TO PAY) EARLY.
 
THIS PARTICULAR STONE WAS BOUGHT IN 2012 FROM A SELLER IN KLEINMOND SOUTH AFRICA WITH THE ORIGEN OF THE STONE INDICATED AS THAILAND. THIS IS INDEED A REAL SAPPHIRE AS THE THERMAL CONDUCTIVITY TEST INDICATE IT SHOWS A HIGH LEVEL 6 THERMAL CONDUCTIVITY CHARACTERISTIC OF SAPPHIRE.
 
STAR SAPPHIRES:
Star sapphires are a type of sapphire that feature a star-like appearance known as an asterism. This asterism is due to an inclusion or flaw in the gemstone but this is one instance where the flaw is desirable.
THERE ARE MANY STAR SAPPHIRE DEPOSITS AROUND THE WORLD, IN LOCATIONS SUCH AS AFRICA AND BRAZIL, BUT THE MOST IMPORTANT DEPOSITS TODAY ARE IN AUSTRALIA, MYANMAR, SRI LANKA AND THAILAND.
Star sapphires can be found in blue, pink, yellow, orange, green, lavender, brown and black.
Star Sapphires are known as a 6-ray chrystal. Due to this natural hexagonal crystal arrangement star Sapphires always parade six rays. When the microscopic inclusions (silky or milky) grow inside the Sapphire, they tend to grow from each corner of the hexagon.
NATURAL OCCURRING STAR SAPPHIRES ARE THE RAREST TYPE OF SAPPHIRE BUT DUE TO THE OPAQUENESS OF MANY OF THESE SAPPHIRE THEY TENDS TO BE LESS EXPENSIVE.
Amazingly you would think Star Sapphires can only be natural but they make synthetic star sapphires and rubies as well by adding one percent rutile (titanium oxide, TiO2) to the starting powder.
 
THIS STAR SAPPHIRE GEMSTONE HAS A SUPPLIED GISA (GEMMOLOGY INSTITUTE OF SOUTHERN AFRICA) CERTIFICATE. THIS COMPANY DOES NOT HAVE A GOOD REPUTATION ONLINE. THEY 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.
 
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 AND SYNTHETIC BROWN SAPPHIRES: USUALLY INERT TO WEAK RED
(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: 14,4mm x 15,5mm x 8,5mm
 
DISCLAIMER: I AM NO GEMSTONE EXPERT. THESE 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 HAVE TRIED TO VERIFY AS FAR AS POSSIBLE ANY STATEMENTS OR CLAIMS BY DOING SOME RESEARCH AND PRELIMARY TESTS ON EACH GEMSTONE.
 
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