what is the complete heat treatment for tanzanite to enhance its color?
442470
"Heating of gemstones to enhance their color goes back centuries. It is considered a natural type of treatment since the process is basically a continuation of the processes that occur in the ground. The stone is heated to a very high temperature, which causes the inclusions (ref. Why Gemstones Have Color in Colored Gemstones 101) to reform themselves and improve the color by making either darker, lighter, more intense, or of a different color. It has been properly stated that without heat treatment the world would be without many colored gemstones. Because colored gemstones occurring in the colors we see are very rare. But heating can take an off-color stone and turn it into a beautiful gemstone. So don't be worried about heat treatment.\n\nCan I wear it everyday?: Heat treatment, for the most part, is permanent. As in the case of the tanzanite shown above. This stone is a brown color coming out of the ground. But turns a beautiful blue/purple (shown at left) after heating. The few exceptions would be kunzite which will tend to fade from its medium pink color to light pink and then colorless in daylight (which is why its called the midnight stone), and yellow sapphire, which can also fade when exposed to direct sunlight.\n\nWhat does this treatment do to the stone?: Basically, it rearranges the atoms in the gemstone. Sometimes, as in the case of ruby, the stone is heated almost to a point of melting, which lets the aluminum oxide in the stone reform to what is basically a new crystal structure. This lets the chromium reform to give off a better color of red. The same can apply to a type of sapphire known as gouda sapphires. These are milky white sapphires that turn blue, and account for many of the promotional quality sapphires out on the market today."\n\n"Heat treatment, for the most part, is permanent. As in the case of the tanzanite shown above. This stone is a brown color coming out of the ground. But turns a beautiful blue/purple (shown at left) after heating. The few exceptions would be kunzite which will tend to fade from its medium pink color to light pink and then colorless in daylight (which is why its called the midnight stone), and yellow sapphire, which can also fade when exposed to direct sunlight."\n\n"Through heat treatment at 500+ degrees celcius the rough tanzanite crystals turn their beautiful purplish-blue color. The rough tanzanite gems are then faceted into various shapes and then marketed to dealers who wholesale the finished gems to jewelry manufacturers and retailers. Tanzanite colors occur in various shades of gray, brown, violet, blue, reddish-purple, and tints of green."\n\n"The raw uncut tanzanite is put in a furnace or oven and brought near its melting point, then held there at that temperature for a period of time, inducing the stone to darken in color as it would in the earth if left to its own. This process may sound simple, but it is far from being an easy or foolproof technique. It is quite possible in this heat treatment process to have the tanzanite melt or overcook, leaving you with a worthless pile of rubble."
579981
Iron and water.  Just wash the sand off the iron.
408690
Get it down to the bare metal by taking it to a shop that does glass beading.  This is very similar to sandblasting.\n\nApply a good primer.  Ideally, you can get access to a pneumatic gravity feed sprayer used on automive finishes.  This will produce a superior finish to the spray can.
1149404
Apply pure turmaric powder mixed with sandalwood paste
457010
It's a complicated procedure! And it really depends on the rough material. \n\nIn the US, Ted Themelis sells special ovens and equipment for heat treatment.  He also gives courses.  You can reach him via his website: http://www.themelis.com/\n\nGood luck!
1045839
GOLD-PLATINUM-PALLADIUM TEST\n\nSelect ore samples suspected to contain Gold-Platinum-Palladium and use concentrates equal to the size of one navy bean or pea. Place the concentrates in a clean test tube and add 1cc Nitric Acid and 3cc Hydrochloric Acid, (this a solution named Aqua Regia which is used regularly when testing.) Boil this over a lamp flame for about 5 to 8 minutes. Should this Aqua Regia solution contain Gold-Platinum-Palladium then the following tests will react with various colors, (good idea to practice on known samples of Gold-Platinum-Palladium for color and reaction identification and become familiar to them.)\n\nTest for Gold (Au).\n\nPrepare a solution for Stannous Chloride for each 8 hour period as this solution does not hold up under extended time periods. Dissolving Metallic Tin (Sn) in Hydrochloric Acid (HC1), where the resulted solution will be called Stannous Chloride (SnC1). Place about 2cc of HC1 in a clean test tube and add 1 or 2 small bit pieces of Metallic Tin to the test tube and bring this to a slight boil. You now have Stannous Chloride (SnC1).\n\nNow begin the gold test by making a spot test with freshly made Stannous Chloride by placing a piece of filter paper onto a clean piece of glass and place one drop of Aqua Regia solution in the center of the filter paper, and then add to this mixture one drop of freshly made Stannous Chloride solution. If gold is present there will show up on the filter paper a purple or rose colored spot when the filter paper has dried; the darker the color the more gold will be present; for low grade ore the spot color will appear plainer. Should the filter paper dry out completely, then add 1 more drop of Stannous Chloride solution to the filter paper to bring out the color.\n\nTEST FOR PLATINUM (Pt)\n\nBegin the test for Platinum (Pt) by placing 20 drops of Aqua Regia solution onto a clean porcelain evaporating dish and boil this over a lamp flame until it is dry, then allow this to remain over the lamp flame for about an extended one second.\n\nPlace the dish where it can cool for a few minutes so as not to break the dish. After cooling, place 4cc of distilled water, (or water free from Chlorine), and reheat just to the boiling point. Filter this solution onto another clean porcelain evaporating dish. Add to this dish, Potassium Iodide equal to one grain of rice. Warm this solution slightly over the lamp flame and observe the color that appears. The results for this test will show if Platinum (Pt) is present as the solution will begin to turn to a light or dark rose color within a few minutes time.\n\nThe more Platinum present in the solution, (ore sample), the quicker and darker the color will appear.\n\nSulphides and other impurities, most likely will give a red color to the solution and will be mistaken for the rose color, if so, then boil off about one-half of the solution to quicken the evaporation process. Then let the porcelain dish set until completely dry, then add a few drops of clean plain water, (no chlorine water). The result will then be a bright rose color, and should there be Sulphides or other impurities in the solution they will appear as colorless. If this solution should appear red, then add a few cc’s of plain water to dilute the dark rose color to a lighter rose color, then you have Platinum (Pt).\n\nTesting for Palladium(Pd).\n\nIn the test for Platinum (Pt), upon adding Potassium Iodide (KI) and warming the procedure, if Palladium (Pd) is present in the sample ore, the solution will turn a dark color or black, which depends upon the amount of Palladium (Pd) present. The more Palladium (Pd) present, the darker the color will be, and also there will be a black precipitate in the bottom of the porcelain dish, which when adding an excess of Potassium Iodide (KI) will dissolve giving a wine-red color appearance.
216675
It all depends on what it was heat treated to. It could be anywhere from 80,000 psi Annealed to Tempered at 950 deg to get 163,000 psi, 1025 deg for 151,000 psi or 1150 deg for 132,000 psi
60081
Try doing flame tests; adding certain compounds to fire make really awesome colors; it's kind of like putting on your own fireworks show.  Check out http://webmineral.com/help/FlameTest.shtml
1004731
Pine cones will create some nice colours in the flames.\n\nYou can treat dry pine cones to produce various colours of flames.  Most of these ingredients can be found in the laundrey section of your grocery store or farm supply stores.\n\nBorax = yellow/green\ncopper sulfate = green/blue\ncalcium sulfate ( epson salts ) = white\nCalcium cloride ( pure only , a bleaching compound ) = blue\n3 parts potassium sulfate/ 1 part potassium nitrate = violet\npotasium  cloride = purple\n\nChoose one colour...do not mix colours\nDisolve as much of the colour as possible in a bucket as you can.  ( typically 1/2 pound of colourant to a gallon of water.)\nMix well\nToss in clean dry pinecones and soak overnight.\nRemove and spread on newspaper for at least 72 hours to dry.\n\nToss in your fire and enjoy the colours.\n\nYou can also achieve the same results by dipping pinecones in parrafin wax and sprinkling with the powdered colourants while the wax is still wet.
567188
Wow it is scary reading some of these answers... Take it to a reputable jeweler in your town and they will test it using  a touchstone and several different types of nitric acid to test. If this is done wrong you could ruin your piece of jewelry.... fire is certainly not your answer... gold meltsssssssssssss..most jewelers and I mean jewelers can tell just by looking, though sometimes even they need to test a piece...
426600
you could get a spray on tan
1087032
try Vogel's "Qualitative Inorganic Analysis", I'm pretty sure it has all the answers 4 u.\n\ndont care editions, but for 7th ed, ISBN is 0582218667\n\n****\nokey then, from Vogels\n\n1) when heated, lead nitrate decomposes to white solid lead oxide (PbO), brown gas (NO2) and oxygen gas. Brown gas decolorizes when contact with water. \n\n2) ammonia odur. ammonium compounds are all volatile towards heat and decomposes to ammonia and an acid but quickly recombine if the acid, in this case, hydrochloric acid, is a strong acid.\n\n3) anhydrate copper sulphate is white, hydrate copper sulphate is blue. I have no idea which one you actually heated. If it's anhydrate, no change; if hydrate, blue ---> white.\n\n4) blue precipitate forms initally, but resolve upon excess reagent, clear blue soln results due to the formation of copper complex [blue precipitate: Cu(OH)2*CuSO4, complex: [Cu(NH3)4]^2+]\n\n5) brown precipitates froms [Cu(OH)2], no change with excess reagents.\n\n6) metal-gray stipe (magnesium stipe) gains a redish brown color due to formation of copper metal. Possible decolorization of the soln (depends on how much magnesium u actually put in)\n\n7) volatile reaction, solid metal solves,ignitable gas is formed. (if phenolphthalein is added to water initally, soln becomes pink)
1171475
Any fine powder ...Talcum powder, lampblack/carbon substances or dye powders can be used. \n\nMore details here: http://onin.com/fp/wwwbd/messages/4/294.html?1137909469
756990
Generally, it stays a gold colour.\nIt will vary with the temperature, between hughes of yellow, almost to white, at high temperature, but not white, and only at really high temperature.\nThere is a green that shows, particularly with impurity, and this may be a trick question. They may call a hugh of yellow, "green", and molten, it is a yellowy/green, light colour at high temparature (superheating, when casting) but essentially, its yellow, or, "gold" colour.\nWhy not paste this as your answer.\n(jeweller 20 years...ive melted the suff!)
23703
Iolite is a mineral sometimes used as a gemstone. Gem quality  a sapphire blue in color to a bluish violet color to yellow gray in color depending on refraction of light It is found in Burma and Sri Lanka. Actually called, cordierite. On the Mohs hardness scale about 7 to 7.5\n The two stones can be confused but are very different and especially when price comes into the conversation as tanzanite is a rare stone that is very very pricey.\nTanzanite is a marketing name by Tiffany & Co. and this stone is not popular with alot of people because of the mining industry of Tanzania. They make a great deal of money off this stone while using methods many people find deplorable. It is still. It is a  purple stone generallly after heat treating because it comes out of the ground a bronze color. It has a Mohs hardnes of 6.5 to 7
487432
You will want to sand your amber with successively finer grades of silicon carbide sandpaper...Going from 220 grit to 400 grit to 600 grit using water to keep the stone cool...Polish with tripoli or tin oxide on a wet piece of leather
65413
I am not going to pick any of those choices because I don't believe any of those are correct, including streak. What you are describing is crystal structure, which might be related to color and streak, but since trace impurities in a mineral often determine color, and streak is nothing more than the color of a powdered form of the mineral I don't think It will be determined by atomic structure with certainty.  Most streaks are white!\n\nCleavage would be a correct answer but it was not included above. Cleavage and crystal structure are closely related properties. \n\nWhat you have described is the crystal structure. All minerals can be classified within 14 basic crystal lattice arrangements of the atoms in three dimensions. These 14 lattice arrangements fit within 7 larger crystal systems, allowing the classification of atomic structure of all known minerals.  To see diagrams of these go here:\nhttp://en.wikipedia.org/wiki/Crystal_structure