“A Diamond is Forever” Jessica Weber CBE 555 Spring 2008.

““A Diamond is Forever”A Diamond is Forever”Jessica WeberCBE 555Spring 2008

OverviewOverviewCarbon/Diamond BackgroundDiamond Market Background

◦ De Beers cartelSynthetic Diamond processing

◦ Companies Starting materials

Synthetic vs. NaturalFuture of DiamondsQuestions

Carbon BackgroundCarbon Background Graphite

◦ Carbon bonds only 3 of 4 possible valence electrons

◦ Crystallographic Class: hexagonal◦ 1-2 on Mohs scale◦ Stable form of carbon

Diamond◦ Carbon bonds all 4 of 4 possible valence

electrons◦ Crystallographic Class: FCC

Crystal Habit: hexoctahedral Cleavage is best done along the octahedral face Diamond cutters take this into account when shaping

a diamond

◦ 10 on the Mohs Scale◦ Meta-stable form of carbon

Kinetically stable rather than thermodynamically stable

Graphite

Diamond

Diamond BackgroundDiamond BackgroundCreating Diamond from

graphite◦ Graphite is compressed

enough that the rings of its carbon atoms form the 3-D atomic structure of diamond High temperatures are

required to retain this structure after the release of the pressure

◦ Activation energy to convert back to diamond is extremely high so once diamond is formed, will not change back to graphite Endothermic reaction

Diamond BackgroundDiamond Background In nature diamonds are created by geologic

processes at more than 150 kilometers below Earth’s surface◦ This is in the mantle region

Crust: 6-35 kilometer thick

Mantle: 2,900 kilometer thick

Core: 3,370 kilometer radius

Pressure/Temperature Chart

Differing geotherms shown

Diamond BackgroundDiamond Background Diamonds rise to the earth’s crust

through small volcanic eruptions (last eruption of this type was 53 million years ago)◦ Just below the surface is a cone-

shaped “pipe” filled with volcanic rock, mantle pieces and diamonds Rock is called kimberlite after the city of

Kimberly in South Africa where these “pipes” were first discovered

◦ Can search for “indicator” diamonds which are present in the kimberlite pipes but are in greater abundance than diamond Examples: garnet and chromite

◦ The majority of diamonds are found where the basement rocks are older than 1.5 billion years

Diamond BackgroundDiamond BackgroundMining Technology

◦Kimberlite is crushed, washed, and screened into different sizes

◦Dense-medium separation is used to produce diamond concentrate Subjected to x-ray fluorescence sorting to

separate the diamonds

◦Dust Management Dust-A-Side company based in South Africa

Uses a natural petroleum resin emulsion to treat the dust in an environmentally friendly process

Diamond BackgroundDiamond Simulants – not made from

carbon, nor have the crystalline structure◦ Cubic Zirconia (1976-Present)

Zirconium Oxide (ZrO2) 8.3 on Mohs scale Differentiation from natural: virtually flawless, CZ is

more dense, mark with a grease pen (will repel)

◦ Moissanite (1998-Present) Silicon Carbide (SiC) 9.25 on Mohs scale Differentiation from natural: virtually flawless, slight

yellow color, double refractive or ansiotropic (diamond is single refractive, isotropic)

◦ Gadolinium Gallium Garnet (GGG) (1972-1975)

Diamond Market Diamond Market BackgroundBackgroundDe Beers is a cartel of companies that trade in

rough diamond exploration, diamond mining and diamond trading.◦ The companies within De Beers are responsible for

about 40% of the world diamond production (value basis).

◦ Diamonds are mined in mainly Botswana, Namibia, South Africa, and Tanzania. De Beers controls 70% of the mining in South Africa, and

planning on opening a mine in Northwest Territories, Canada (2007).

◦ “A Diamond is Forever” was coined in 1947 De Beers spends $150 million a year on advertising

◦ Only one diamond mine in US – Arkansas Only mine open to the public to mine your own diamonds More than 70,000 diamonds have been discovered there

Diamond Market Diamond Market BackgroundBackgroundDe Beers’ Legal Matters In 1999, De Beers stopped all outside buying of

diamonds in order to guarantee categorically the conflict-free status of De Beers diamonds◦ De Beers guarantees that 100% of the diamonds it now

sells are conflict-free In 2004, De Beers paid a $10 million fine to the United

States Department of Justice to settle a 1994 charge that De Beers had conspired with General Electric to fix the price of industrial diamonds ◦ example: abrasives on drills

De Beers currently holds a legal exemption in South Africa from the mandatory dust suppression method of spraying water when drilling◦ Stating that the dust in its mines is “uniquely” harmless

Diamond Market Diamond Market BackgroundBackgroundRAPAPORT Diamond Report

◦ Monthly wholesale diamond price list used by dealers worldwide to keep up with changing market prices

◦ Should be paying less than price on diamond report

◦ Dealers could charge very different prices for “similar” diamonds

Internet buying of Diamonds is bringing market cost down

Market uses 4Cs to describe a diamond◦ Cut, Clarity, Color, Carat

Synthetic ProcessingSynthetic ProcessingCompanies using GraphiteCompanies using Graphite

CARAT*BetterThanDiamond

◦web-based Gemesis

◦FloridaApollo Diamond

◦Massachuesettes

**Companies producing synthetic diamonds for jewelry purposes


First Diamond synthesized occurred in the 1950s by General Electric◦ Now the largest producer of synthetic diamonds

The invention of tungsten carbide in (1930s) offered a material that could withstand the extreme pressure needed for growing a diamond.

Use of metal catalysts in synthetic diamond processing lowers the activation energy◦ These metal catalysts are the reason for the color impurities


Process 1◦ High-Temperature High-Pressure (HTHP)

Uses a four-anvil tetrahedral or a six anvil press Uses belt or cubic press

Belt press: pressure is confined radially by a belt of steel bands

Cubic press: provide pressure simultaneously to all sides of a cube shaped volume (typically smaller than belt press, so can achieve pressure and temperature faster to create diamonds quicker

Heat (3000°C) and pressure (50,000 psi) are applied in which the growth process takes approximately 7-10 days to complete

Largest diamond produced from this process is a 34.80 carats, made by De Beers (1992)


Process 1 Using the capsule shown

◦ Small diamonds are placed at the bottom to serve as “seeds” for the growth of larger diamonds

◦ An electrical current is passed through the conductive graphite, which heats in response Clay acts as a thermal insulator as

well as a container for pressure

◦ Graphite dissolves into molten metal catalyst (iron or cobalt)

◦ Precipitates as diamond on the “seeds” which are colder at the bottom Takes a few days to grow diamonds

a few mm across


Process 2◦ Chemical Vapor Deposition (CVD)

Developed in 1980s Lower pressure (less than 1atm) and temperature (800°C)

than HTHP A diamond “seed” is placed in the growth chamber heat

and pressure are applied as well as a vaporized carbon plasma, combined with hydrogen applied to the substrate in layers. The vaporized carbon gases are energized using microwave

energy Process takes 3-4 days to complete CVD diamonds can usually be identified by an orange

fluorescence “Thin film diamonds” are produced using this process

Used in industry as coatings to draw heat away from electronic components and coatings for transparent windows


Current Industrial UsesMachining

◦ Diamond Powder Used for manufacture of diamond tools and as a free

abrasive◦ Diamond grinding wheels

Used to machine grind crystal glass Used in processing of ceramics and precious stones

Electronics◦ Conductive diamond is a useful electrode◦ LEDs and lasers in UV region

Medical◦ X-ray lithography masks

UW-Madison Prof. Robert Hamers Developed photochemical methods for covalently linking

DNA to the surface of polycrystalline diamond films produced through CVD

Synthetic ProcessingSynthetic ProcessingCompanies using Companies using

RemainsRemains LifeGem◦ Based in Chicago◦ Founded in 2001◦ Uses human and pet remains, as well as hair

GemSmart◦ Based in San Diego, California◦ Founded in 2002◦ Uses human and pet remains

Algordanza◦ Based in Switzerland◦ Founded in 2004◦ Uses human remains only

Heart-In Diamond◦ Based in Russia◦ Uses hair only

Synthetic ProcessingSynthetic ProcessingCompaniesCompanies

LifeGem◦Founded in 2001

3 years previous of research, with a patent pending for LifeGem

Currently creates .2-1.5 carat diamonds but hoping for diamonds as large at 3 carats in a few years.

Can create over 100 diamonds from one set of remains Either 8 ounces of ash or the equivalent of hair

Made $7.5 million in revenue in 2006 ◦Unique to LifeGem

Created a diamond from the hair of Ludwig Von Beethoven

Synthetic ProcessingSynthetic ProcessingLifeGemLifeGem

Process 1. Capture carbon from

remains of a standard cremation or from a lock of hair 8 ounce portion Using high nitrogen, low

oxygen atmosphere to do collection

2. Purification by using extreme heat to convert the ash into graphite Use crucible that can

withstand 3000°C to convert the ash into graphite Crucible is marked to ensure

traceability Use 16 digit tracking number


Process 3. Creation, crucible is

placed in a “diamond press” where extreme heat and pressure are applied Longer time in press creates a larger diamond

Pressure used is nearly 1,000,000 psi

Use a octahedral diamond growth chamber “Inside precisely calculated

variables of heat and pressure cause the purified carbon (graphite) to break down into individual atoms and crystallize into a rough diamond. “


4. Certification, done by gemologists trained by the Gemological Institute of America (GIA).

◦ Length of time For LifeGem to create a yellow diamond it is approximately

6 months and approximately 9 months for a blue diamond.


LifeGem pricing*.50-.59 carat size

Type Price

Blue LifeGem Diamond $7,899

Colorless LifeGem Diamond $7,899

Red LifeGem Diamond $7,299

Green LifeGem Diamond $7,299

Yellow LifeGem Diamond $5,999

Synthetic vs. NaturalSynthetic vs. NaturalComparison

**(80 tons produced for industrial use)

Price.50-.59(colorless)

Percent different than Natural

Carats Produced

Hardness(Mohs)

Synthetic$212 -81.4% <5,000 ** 8.5 -9.0

LifeGem $7,899 +692.3% -- --

Natural $1,141 -- 120 million

10

Synthetic vs. NaturalSynthetic vs. NaturalDifferentiation:

◦ Synthetic diamonds usually have a yellow color to them. This is caused by nitrogen impurities Other colors may also be reproduced such as

blue, green or pink These result from the addition of boron or from irradiation

after synthesis

◦ Some companies have added nickel to synthetic diamonds to them to help discern from natural diamonds

Synthetic vs. NaturalSynthetic vs. NaturalDifferentiation:

◦ De Beers uses DiamondView tester Tester uses UV fluorescence to detect trace

impurities of nickel or other metals in HPHT diamonds, or hydrogen in CVD diamonds.

◦ A claimed apparatus is one that uses a magnet field to determine the difference Place a diamond, natural or synthetic into the

magnetic field Detect the alternating current generated by

rotating the diamond Speeds as high as 25,000-30,000 rpm

Process the signal (Patent 6281680)

Future of DiamondsFuture of DiamondsSpace shuttle

◦ Diamond windows◦ Diamond radiation detector◦ Flat panel displays with diamond-powered pixels

Recently it has been discovered that if buckminsterfullerene is used instead of graphite, lower pressures can be utilized, as well as ambient temperature for synthetic diamond formation◦ (20+5 Gpa or about 20,000 atmospheres)◦ This is an exothermic reaction◦ Lower energy requires no catalyst

Interesting FactH.G. Wells described making synthetic

diamonds in novel, “The Diamond Maker” (1911)

Questions?Questions?Creating Diamonds from remains How are the remains purified to graphite; heated, then how is it separated? Where does the extra starting material go?

◦ Is it sent back or disposed of?

What if I have less than the requested amount of material? ◦ We have been able to make a diamond out of as little as a tablespoon of cremated

remains or a few small wisps of hair. The amount of remains or hair will not affect the size of the LifeGem diamond your order. You can order any size Option Range. (Source: LifeGem)

Synthetic Diamonds I know starting material is carbon, but from where? (Biomass, pure

graphite?) Passing off synthetic diamonds as real for “upgrades”? – In St. Thomas I expected the cost of applying extreme heat and pressure to be so high that

synthetic diamonds would be cheaper, but not the case. (I know that HTHP is cheaper)

Natural Diamonds If the last kimberlite eruption was 53 billion years ago, and we mine 120

million carats a year, how long until the diamond supply runs out?

SourcesSources http://www.diamondhelpers.com/ask/0037-whatisrapaport.shtml “RAPAPORT, price list: What

is it?

http://www.gia.edu/gemsandgemology/29630/synthetic_diamonds_book.cfm

http://www.amnh.org/exhibitions/diamonds/growing.html , “Growing Diamonds,” American Museum of Natural History

http://www.khulsey.com/jewelry/synthetic_diamonds.html , Synthetic Diamonds and Diamond Stimulants.

http://www.informativepost.com/2008/02/18/Diamonds-Graphite-345.htm “Diamond and Graphite,” Informative Post

http://www.snopes.com/science/diamonds.asp

www.wikipedia.com “LifeGem”, “Synthetic Diamond”, “Diamond”, “Fullerene”

http://chemistry.about.com/cs/geochemistry/a/aa071601a.htm “Chemistry of Diamond”

http://www.gemsmart.us/Order.asp

http://www.heart-in-diamond.com/

http://www.diamondlive.org/Home/tabid/849/Default.aspx

http://www.chem.wisc.edu/~newtrad/CurrRef/BDGTopic/BDGtext/BDGDmnd.html

http://www.alwoda.com/files/20050505_SYNTHETIC_Diamonds.html “Synthetic Diamonds”

http://www.cisp-publishing.com/book40.htm “Science and Technology of Diamond” Cambridge International Science Publishing

http://www.patentstorm.us/patents/6281680-claims.html “Method and apparatus for

distinguishing synthetic diamonds from natural diamonds”

“A Diamond is Forever” Jessica Weber CBE 555 Spring 2008.

Documents

Transcript of “A Diamond is Forever” Jessica Weber CBE 555 Spring 2008.