Presentation on theme: "The Science of Natural and Synthetic Diamonds"— Presentation transcript:
1The Science of Natural and Synthetic Diamonds The “Millennium Star” is currently the most valuable diamond on Earth... “priceless” (never been sold)It is insured for $100 million
2Pure Carbon Minerals on Earth Diamonds & Graphite
3Mineral -- Definition starts as follows… Naturally occurring, inorganic solids …Man-made made minerals not from a living organism, require the adjective thus “amber” which is a natural“synthetic” in front carbon-rich “pine sap” isthe mineral name “organic” and is not a mineral.Research commissioned by the Diamond Trading Companyshows that94% of women preferreal diamondsto synthetic diamonds.
12Brazil’s alluvial diamonds are hundreds of miles from the pipes… most of the pipes are “undiscovered”X-ray the gravel…diamonds willfluoresce in blue
13Diamonds in Kimberlite Matrix Real CrystalsIsometric“cubic”Alluvial DiamondsOften“Cleavage Fragments”
14How can a “Cubic” Crystal become an Octahedral Cleavage fragment ? Start with “red” cube, break off each cornerin yellow…. End ups with octahedral cleavagefragment…
15Lieber & Solow is one of oldest clients of the DTC Diamond Trading Company in London. We are one of only a handful of industrial Sightholders worldwide. As such, we are able to consistently keep in inventory a full range of products. A full-time staff manufactures parcels of wire dies, dressing tools, coning tools, shaping tools, form tools and drill bits
16Natural Diamond Crystal Are “Isometric” the most common pure shapes are….. Dodecahedron:Twelve sides“diamonds”Cube:Six sides“squares”Octahedron:Eight sides“triangles”Tetrahedron:Four sides“triangles”1916 Goldschmidt’s500+ drawings ofDiamond Crystal Shapes….
171916 Goldschmidt’s 500+ drawings of Diamond Crystal Shapes….
23Approx 20% of all mined diamonds are cut into gems, and the majority of the rest are used in Industry Natural uncut Diamond crystals are more of a rarity to be owned, for several reasons – they are highly valued as a cut stone, therefore it is difficult to obtain high quality natural uncut crystals outside of the gem trade, and they are often very small in size.Micromount$4500.7 cm … ¼ inch
24The Oppenheimer Diamond At 254 carat (50 gm) this yellow natural octahedral crystal isthe largest uncut diamond “crystals” in the worldDiscovered in 1964 the stone was presented to the Smithsonian Institution in memory of the late Sir Ernest Oppenheimer, who started De Beers.1 inch
25“Aurora Collection” ( contains no diamond crystals) In Paris, Don Pedro Davilla (ca.1775), had a mere 16 diamond crystals in his enormous collection of over 8,000 total diamond specimensPaul Seel (1982) assembled the world’s largest collection of several hundred diamond crystals, each of which "illustrated some morphological fact"
26Cut diamonds increase in value over 5x A 603 Carat Diamond comes from Lesotho - South Africa; named the "Lesotho Promise“ – sold for $12 millionLesotho Promise Diamond necklace cut from one stone into 26 jewels – $60 million
27Diamonds are the most valuable commodity on earth based on dollar value per weight. The “Hancock Red” weighs only 0.95-carat, is purplish-red and sold for nearly $1 million.One carat is equal to oz.This is $14 ¼ million / oz.A diamond’s value can be more than 200,000 x greater than an equal weight of gold
28A proper “cut” causes colors to appear Diamond has highdispersion… bendsred light much morethan it bends blue light
29The Cullinan Diamond is the Star of Africa The world’s largest gem-quality uncut diamond was found in 1905 and had a weight of carats (approx 1.5 pounds).The fragment was cut into 105 gemstones, the largest is carats known as the Star of Africa, which is in the British Royal Scepter located in the Tower of London.The crystal morphology suggests that this diamond is in fact only a cleaved section of a larger octahedral crystal, which has never been found.The nine largestof the 105 piecescut into gemstones
30Law of Constancy of Interfacial Angles Contact angle for quartz pyramid is……………………………… 46 oContact angle for diamond octahedron is …………….…. 70 ½ o
31The “Golden Jubilee” at 546 carats The Unnamed Brown became the Golden Jubilee when King Rama IX of Thailand (also known as King Bhumibol Adulyadej the Great) was given the stone to the 50th anniversary of his coronation in 1997.Not many people in Thailand know that the Golden Jubilee is a diamond, as the government decided to tell its people that the Golden Jubilee is a large golden topaz
32The previous record price paid for any polished diamond was $16 The previous record price paid for any polished diamond was $16.5 million for a carat stone, the Star of the Seasons, that was auctioned by Sotheby's in 1995, thus selling for about $165,000 per carat.“Priceless”…. Insured for over $100 million
33The Millennium Star was part of the Splendor of Diamonds Exhibition at the Smithsonian Museum in Washington DC over the summer of 2003
34Use of the “octahedral cleavage” as a diamond cutter… If your laser cut is not along the cleavage direction, when you hit the diamond for the first “cut” it will shatter.
36Piqué is a tiny black spot caused by undigested carbon inclusions (natts) within diamonds. Black material found within a diamond's internal cleavage planes is often graphite
37Carbon piqué inclusions are sometimes removed by diamond enhancements such as laser drilling, which can leave their own types of unique inclusions.
38All of the microscopic diamond inclusion photography in this talk was generously contributed by the AGSL gemological testing laboratory in Las Vegas, Nevada, and is reproduced with their permission.
39Partial octahedral cleavage forming around a stress point Feather “Inclusions”Partial octahedral cleavage forming around a stress pointSee triangles… See garnet causing stress Cleavage Plane = rainbow
40Liquid filled inclusions where faces meet = lines Tube InclusionsLiquid filled inclusions where faces meet = lines
41Mantle minerals captured by the diamond as it grew Crystal InclusionsMantle minerals captured by the diamond as it grewChrome Diopside Pyrope Garnet Grossularite Garnet
42Twinning Wisps Inclusions … bubble on surface between two twins Twinning Wisps will oftencreate stress and causea feature inclusion to form
43Inscriptions are … embedded graphite in a laser cut Clarity… One of the 4C’s… in a cut stone…How to evaluate the inclusions….
44Color in Diamonds result from inclusions of other elements & defects within the diamond lattice Yellow is the most common colour, and minute inclusions of nitrogen will give yellow huesRare colors such as blue and pink are highly prized in cut gems…Boron will create a blue colorMissing carbon atoms in the atomic lattice, called defects, will cause a diamond to turn pink or red.Artificial lattice defects…dueto irradiation causes greenand/or black diamonds.
45Natural red & pink are most valuable Pink Diamondsfrom the Argyle-MineAustraliaChocolate Diamonds
46Chemical Vapor Deposits (CVD) Synthetic Diamonds….High Pressure & High Temperature (HPHT)(maximum size about 6 carats)enormous energy costsChemical Vapor Deposits (CVD)Growth rate of a millimeter / dayon the surface of an (100) wafter
48Chemistry of Chemical Vapor Deposits CVD Diamonds Chemical injectedHigh temperature breaksBonds and strips electronsC deposited on substrateas both graphite and diamond;but H+ etches the graphiteoff to form CH gas leaving justthe diamond on the substrate
49Fluoresence of CVD diamonds … is orange to red…not the blue of natural diamondsTypical anomalous double refraction due to strain caused by plastic deformation --‘Tatami Defect’ is found only in natural diamonds….CVD diamonds are strain free
50The Future … Turning unusual carbon forms directly to diamond
51Is Z-pinch the future? A recent posting on the diamond blog… So, will a 10,000 Amp current heat a 0.001" graphite fiber to at least 3000º K at needed pressures? Graphite has a resistivity of microohm-cm at 20º C. If we have a one cm length of fiber, it will have a resistance of ( W-cm)(1 cm)/p( cm)2 = 271 W. The rate of power dissipation will be (10,000 Amps)2(271 W) = 27.1 X 109 Joules/second. At 3000º K graphite has a heat capacity of 2.5 Joules/gramºK. Our hypothetical fiber contains 1.3 X 10-5 grams of graphite. To raise its temperature from 295º K to 3000º K will require (2.5 J/gºK)(1.3 X 10-5 g)(2705º K) = 0.09 Joules of energy. At a power level of 27 GW, this will take only 3.3 X seconds. No problem. I am convinced that this method of diamond synthesis of carbon fibers will work.
52Modern Diamond Scientists I’m afraid the numbers don’t lie Norton,We’re definitely nerds…that may be true Henry…. but we are very rich !!
53Exploring in North America for new diamond deposits
54Where can you get Diamonds in N. America? In your dreams…..Not worth it….
55Crater of Diamonds State Park Murfreesboro, Arkansas Thirty-seven acres of diamond producing “plowed” field within a single crater, is the only site in the world where diamonds are regularly found and is open to the public
56Archean-age Rocks on the surface... vs … under sediments USA -- Unexplored diamond pipes are in the “Wyoming” Province
57Over 400 Unexplored “potential” Diamond Localities in Colorado, Wyoming, & Montana Rocks in region must be early Precambrian in age … > 1,500 million years oldExplosion pipe must be present… seen as depression lake without drainage
58Over 400 Unexplored “potential” Diamond Localities in Colorado, Wyoming & Montana …. Rocks must be “brecciate” into pulverized fragments… blue ground helpsA drop of acid on the soils will cause it to “fizz”…. Lots of carbonatecauses a vegetation“anomaly” .. Iron Mnt. Colo.
59Over 400 Unexplored “potential” Diamond Localities in Colorado, Wyoming & Montana …. You will find fragments (xenoliths)ofmantle material – peridotiteand eclogite – (olivine & garnet)You will find gem quality fragments of associated minerals….red pyrope garnet = Cape Rubygreen chrome diopside = Cape Emeraldgreen olivine = Peridot
60Over 400 Unexplored “potential” Diamond Localities in Colorado, Wyoming & Montana …. How to “recognize” that diamond in the rough when you find it……Diamonds are called 'ice‘ by many prospectors because its excellent thermal conductivity attracts heat. When touched to your lips, it will conduct heat away from your lips and give a sensation of feeling cool. 200x greater than copperTake a quartz crystal with you. A diamond will easily scratch the face of the quartz (don’t use “glass” because all associated minerals will scratch the glass).One of the easiest methods is to use a relatively inexpensive device marketed as a 'Diamond Detector' or 'Diamond Detective‘ at about $99, which measures the conductivity.Set up a small “grease board”:diamonds repel waterand are attracted togrease
61Over 400 Unexplored “potential” Diamond Localities in Colorado, Wyoming and Montana Iron Mountain, State Line, Sheep Rock districts of ColoradoKelsey Lake, Colo… waste dump (6.2 carat stone in 2003)Leucite Hills in SW Wyoming … diamonds foundTwin Mountain Lakes, Wyoming is a major district of 50+ volcanic explosion crater found sitting within view of Interstate 80 west of CheyenneIndian Guide district in Wyoming (west of Chugwater)Happy JackThere are explosion deposits south of Laramie1996 – 2000
62Chuck Fipke Nick-named "Stumpy" and "Captain Chaos" A short, absentminded Canadian geologist named Chuck Fipke, discovered diamonds in Lac de Gras, Northwest Territories, in 1991, he started the largest staking rush in North America since the great gold rush.
64Ekati and Diavik diamond mines at Lac de Gras on the Slave Craton became North America's major “commercial” diamond minesThe Ekati opened in 1998…There are 156 known kimberlites within the EKATI block of claims and 41 are known to contain diamondsDiavik, on an island in Canada’sNorthwest Territories,began production in 2003(ice road trucker are usedto move all provisions)