LARGE 25.0CT SKY BLUE TOPAZ GEMSTONE WITH BEAUTIFUL ROUND CUT IRRADIATED FOR 3 MONTHS

AN BEAUTIFUL LARGE 25.0 CARAT SKY BLUE TOPAZ GEMSTONE WITH A BEAUTIFUL ROUND CUT. IT IS ALSO CALLED A CLOUD TOPAZ AS IT RESEMBLES THE SOFT PALE BLUE COLOUR OF CLOUDS. COMES WITH A BEAUTIFUL PERSPEX PRESENTATION CASE AND VELVET BAG.
 
THIS PARTICULAR STONE WAS BOUGHT FROM A SELLER IN CHANTABURI THAILAND WITH THE COUNTRY OF ORIGEN NOT SPECIFIED. 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 AN HEAT TREATED OR IRRADIATED TOPAZ GEMSTONE WHICH MEANS THE COLOR OF WHITE TOPAZ WAS ENHANCED BY HEAT TREATMENT. IN PARTICULAR OUR STONE IS WHAT IS CALLED A SKY BLUE TOPAZ WHICH IS THE LIGHT BLUE INTENSITY OF TOPAZ WHERE WHITE TOPAZ HAS BEEN IRRADIATED FOR 3 MONTHS TO CHANGE THE COLOR.
 
THE 3 BLUE COLORS OF TOPAZ:
SKY BLUE TOPAZ IS THE LIGHTEST COLOR OF BLUE TOPAZ WHERE WHITE TOPAZ IS IRRADIATED FOR 3 MONTHS TO CHANGE THE COLOR.
SWISS BLUE TOPAZ IS THE MEDIUM COLOR OF BLUE TOPAZ WHERE WHITE TOPAZ IS IRRADIATED FOR 2 YEARS TO CHANGE THE COLOR. IF YOU ASK ME THIS IS THE MOST BEAUTIFUL OF THE BLUE TOPAZ. ITS VALUE IS AROUND $25 PER CARAT.
LONDON BLUE TOPAZ IS THE TOP COLOR OF BLUE TOPAZ WHERE WHITE TOPAZ IS IRRADIATED FOR 4 YEARS TO CHANGE THE COLOR. IT IS A INKY GREY KIND OF BLUE
 
I THINK THAT IT IS INDEED A REAL TOPAZ GEMSTONE AS IT PASSED OR GAVE AN UNCLEAR ON ALL THE TESTS I COULD PERFORM:
PASSED THE SCRATCH TEST: IT SCRATCHES GLASS EASILY IT IS HARDER THAN GLASS.
(MOHS HARDNESS GLASS 5.5-6.5 TOPAZ 8.0)
PASSED THE ELECTRON UV LIGHT EMISSION TEST: NO UV REACTION. NATURAL BLUE TOPAZ SHOULD SHOW A MODERATE YELLOW OR GREENISH TO NO REACTION UNDER UV LIGHT. IRRADIATED TOPAZ LIKE A SKY BLUE SHOULD ALWAYS SHOW A WEAK TO NO REACTION. (Topaz is often treated with heat or irradiation to make it a deep blue, reddish-orange, pink etc)
(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.)
UNCLEAR 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 4. FOR TOPAZ A LEVEL OF 5 TO 6 IS THE NORM FOR THIS TESTER.
(WITH THIS TESTER GLASS NO MOVEMENT AND QUARTZ ONLY MOVE UP LITTLE TO NO 4.)
 
SIZE: 21.0mm x 21.0mm x 10.90mm
 
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 THOROUGH RESEARCH AND PRELIMERARY TESTS ON EACH GEMSTONE.
 
TOPAZ:
Topaz is a semi-precious gemstone formed from magma deposits. Chemically its made up of silicone, aluminum, and fluoride. Certain chemical impurities and differences will give it a unique color and appearance. Today, topaz deposits are found in Brazil, United States, Madagascar, Myanmar (Burma), Namibia,  Zimbabwe Mexico, Sri Lanka, Pakistan, Russia, and China.
Common topaz in its natural state is colorless, though trace element impurities can in rare instances make it pale blue or golden brown to yellow orange. Topaz is often treated with heat or radiation to make it a deep blue, reddish-orange, pale green, pink, or even purple.
Color is the most important factor for Topaz. Irradiated Blue topaz and colorless topaz are very affordable and widely available. Natural occurring red, pink and orange colors are rare and valuable. Blue topaz, the most common variety seen in jewelry today, has been produced in such quantities that today it is generally available for $25/ct. at retail for ring sizes. Larger sizes may be slightly more. While natural blue topazes are known, the huge production of treated blue topaz has essentially dropped the price of the natural blue down to that of the treated stone.
 
PLEASE ALSO SEE MY OTHER ITEMS LISTED. I HAVE SOME OTHER GEMSTONES ALSO ON AUCTION THIS WEEK.