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Diamonds Under the Scope

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Diamond Inclusions: Diamonds are formed deep under the earth’s surface for millions of years under extreme heat and pressure. Naturally, this give rise to a number of imperfections inside a diamond, which are called inclusions, as well as on its surface, which are called blemishes. When viewed under a 60X or a 120X microscope, the inclusions of a diamond reviewed a fascinating world.

The article below is written by Sharon Bohannon of GIA and is reposted here from www.gia.edu

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Diamonds Under the Scope

Another world exists in gemstones when they are viewed through a microscope. Landscapes and whimsical creatures appear to come to life as you explore a gem’s internal features and formations.
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Inclusions spin a tale of provenance and tell of the diamond’s journey from deep within the earth to the surface. They are a geological time capsule that tells a story of a gem’s formation. Feather inclusions in a diamond, for example, can be indicative of a rough ride from the earth’s mantle to the surface. These birthmarks are signs of a diamond’s natural origin and make your diamond unique in the world.

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In 1645 an Englishman saw a red crystal inclusion (probably a garnet) in a diamond belonging to a Venetian nobleman by the name of Rugini. This discovery sparked an interest in colored crystal “guest” minerals or inclusions in diamond. A number of crystal mineral inclusions have been reported since then.

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Inclusions impart character, beauty and essence to their host gems.

Dr. Edward J. Gübelin  

The renowned Swiss gemologist Dr. Edward J. Gübelin (1913-2005) built a legacy on the study and systematic classification of the internal world of gemstones. His research demonstrated the importance of these internal features in determining a gem’s identity.

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John I. Koivula, GIA’s analytical microscopist and long time chief research gemologist, wrote to Dr. Gübelin as a teenager, sending along his first photomicrographs (photos taken through a microscope). This began a collaboration that would culminate in the three-volume “PhotoAtlas of Inclusions in Gemstones,” landmark works that established the importance of inclusions as an aid to identifying gemstones. Their photomicrographs of inclusions illustrate common features in gemstones from particular localities. Their richly illustrated tomes also help separate natural from synthetic or treated gemstones, including diamonds.

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Diamonds present some of the most striking inclusions to view under the microscope and host a variety of gemstone guest crystals. Some of the most frequently found are pyrope garnet, olivine or peridot, diopside, chrome-spinel, and much less frequently, ruby and sapphire. Diamond crystals are also frequently seen as inclusions within diamond itself.

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The study and documentation of inclusions in diamond has inspired poetic and descriptive names: feather, cloud, halo, knot, needle, bearding and pinpoint.  With magnification, these scenes are clues to the natural origin of a diamond and give you a renewed appreciation for its characteristics and qualities. The possibilities of what you can see in these photomicrographs is almost endless.

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The Centenary Diamond

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The Centenary Diamond Owned by De Beers

The Centenary is one of the world’s largest modern cut diamond weighing 273.85 carat, measured 39.90 × 50.50 × 24.55 mm, and had 247 facets – 164 on the stone and 83 around its girdle.

The Gemological Institute of America (GIA) (Read here for GIA gemologist class) graded its color as D (Read here for color of Diamond) and its clarity as Flawless.   The rough diamond weighed 599 carats and was found in July 1986 in the Premier Mine in South Africa.

Using the most sophisticated electronic cutting instrument at that time it took the famous master cutter Mr. Gabi Tolkowsky three years to prepare, cut and polish this stone.

Specialized Equipment Being Used To Cut The Centenary Diamond

The equipment used for cutting this stone is specifically designed to hold it securely with pipes to circulate cooling liquid.  The small blue wire is connected to a 9 thermal probe to monitor the temperature generated during the cutting process.

The Centenary Diamond is owned by De Beers Consolidated Mines Limited and was unveiled for public view for the first time in London on May 1st 1991 by De Beers’ Deputy Chairman Mr. Nicky Oppenheimer.

What a stunning beauty in so small a stone….

Citation & Sources : http://en.wikipedia.org/wiki/Centenary_Diamond, http://famousdiamonds.tripod.com/centenarydiamond.html

Rapaport: Diamond Prices Rose 10% Last Year

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Abstract : Rapaport Report Dated December 31, 2010

The Rapaport Group reported in its communiqué dated January 7, 2010 that that polished diamond prices went up by 10.3% in 2010 following a decline of 7.6% in 2009.  It reported that prices for 0.50ct increased by 4.1%, 1.0ct by 12.3% and 3ct by 24.6%.  Prices at Rapaport Melee Auctions also increased by 57%.

Rapaport estimates that average prices for rough increase by about 21% in 2010.

US holiday sales meets expectations and dealers hope that the positive demand will extend to the Far East in view of the coming Chinese New Year on February 3, 2011. Cutters concerned mining companies may raise rough prices following strong 4Q rough sales. Israel’s 2010 polished exports +48% to $5.8B, rough imports +51% to $3.8B.  Investors start 2011 bullish as Dow reaches two-year high (11,722.89)

The group also reported that:

1) Large, high quality diamonds did well in 2010, as did small, inexpensive diamonds.

2) With more than 600,000 cutters, India now dominates diamond production, assisted by easy banking credit and a powerful local jewelry market that is growing at about 25 percent a year.

3) Diamond producers’ stockpiling and cuts in production created shortages that resulted in speculative pricing and reduced manufacturer profits.

“While the U.S. recovery will take time, the global diamond markets are well positioned for growth in 2011,” said Martin Rapaport, chairman of the Rapaport Group. “The trade is advised to enjoy the ride as long as interest rates remain low, avoid speculation and maintain liquidity.”

Note: Last year we sold a number of 1ct and above solitaire diamonds to be set as wedding and engagement rings.  Our clients have been calling us expressing their appreciation.



Costly Crazy Carbon Crystals – The 4Cs Of Diamond

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This afternoon three of us were having a jolly good time and a cuppa coffee at Starbucks.  ET was in town together with another ‘brother’ of us.  Looks like we have not seen each other for umpteen years, each of us has gone to a different war zone answering the call to arms, doing our patriotic duty and all that jazz.   We did some back slapping, traded some silly jokes and laughed at everything and nothing.

These two are some corporate big wigs who always find time for me when they are in town and give me some serious freebee advice on the next step to take.

So Brother Number One asked,”Hey, A ARTHUR LAU, what are you going to write tonight?”, as he articulated with heavy emphasis on my full name.  He and ET had told me to use my full name in order to be recognized fast on cyberspace.  No half measures and don’t confuse people when I am known by A at one time, Arthur at another time or Lau at some other time.

I must be known as A Arthur Lau, period.

“Thinking of writing some Diamond fundamentals like the 4 Cs, just to fill out some blanks and make it complete”.   I remarked casually and continued. “But that subject has been BTDed,  Blogged To Death.”

“Oh yes! the 4 Cs of diamonds, Costly Crazy Carbon Crystals”.

I bolted upright and nearly spewed my latte. ET laughed. That was a real gem of a wisdom in his words. In all my years as a dealer, this was the first time I heard this phase.  We hi-5ed each other and congratulated Brother Number One for his flash in the pan wit.

Now my train of thoughts sped through my scrambled brain faster than the speed of light.  Writing about the 4 Cs is just too plain, nobody will give two hoots, there are tons of literature on the net by highly respected authorities on the subject matter. BTD. I have to approach it at another angle, give some of my thoughts and opinions on it and question some long held established answers.

But as I said before, I have to include some fundamentals first.  So just gloss over the following or skip it if you like.

The actual 4 Cs of Diamonds are Carat, Color, Clarity & Cut as defined under the International Diamond Grading System by the Gemological Institute of America, GIA:

1) Carat is the weight of the diamond. 5 ct = 1 gm or 1 ct = 0.2gm. In the diamond trade 1ct = 100 points.

Read the chart below to get some idea of how big a diamond is when it is of a certain weight.  A 1ct round diamond has a diameter of 6.4mm.

2) Color – the color of a diamond ranges from D to Z.

D E & F are defined as Colorless, G H I and J color are defined as Near Colorless, K L M are defined as Faint Yellow, N O P Q R are defined as Very Light Yellow while S to Z are defined as Light Yellow. Beyond Z color is known as Fancy Colored Diamond and is denoted by Z+.

3) Clarity is defined as the degree of blemishes or inclusions within the diamond or on its outer surface.  This is based on examination of the diamond under a 10x loupe.

Clarity Grading For Diamond

The GIA has 11 clarity grade.  These are Fl (Flawless), IF (Internally Flawless), VVS1-VVS2 (Very Very Small Inclusions), VS1-VS2(Very Small Inclusions), SI1-SI2 (Small Inclusions), I1-I2-I3(Imperfect eye visible inclusions).

4) Cut – this is not the shape of the diamond as many people thought it to be.

Cut is what we call ‘make’ of the diamond.  It defines how well and how proportionate is the cutting to bring out the fire and brilliance of a diamond.  The grades are Excellent, Very Good, Good and Fair.

Objectivity & Subjectivity

One might ask the following questions to this grading system:

  1. 1. Carat is clear, precise and objective.  The weight can be taken up to 2 decimal point of a carat and this is easily done with a precise weighing scale.

  1. 2. Color can be subjective as it is only a definition and not an absolute scale. So what is the main difference between a D color diamond as compared to an E color diamond.  How would one put an absolute number to the definition of Near Colorless?

  1. 3. Clarity is also subjective as it is a description of the inclusions from within and from without the stone.  What is the difference between VVS1 and VVS2?

  1. 4. Cut is also another description with no absolute scale.  How would you separate Excellent Cut with Very Good Cut?

When you attend the Graduate Diamond course by GIA you would have been stumped at first.  You would have thought that this is not a precise science, utilizing some subjective descriptions to assign a grade. But as you go along the learning curve you will then see the beauty of the system.

The International Diamond Grading System by GIA has evolved since the early 50s and it has established the stringent standards that revolutionized the whole diamond industry. It is the 100% consistency that makes the GIA Diamond Grading Report the premier and the international sole authority on grading of diamonds that are used and trusted by all the diamond dealers of the world.  That is, if you send a diamond for grading at GIA, Los Angeles and to GIA New York City, the GIA Diamond Grading Report will be the same.

GIA Campus At Carlsbad at California, USA

There is no subjectivity to it.

So if you have Cash (the 5th C) buy a diamond that is accompanied by a GIA Diamond Grading Report.

Hmm, I still like the Costly Crazy Carbon Crystals – the 4 Cs of Diamond.  Thanks Din, owe you one.

Koh-i-Noor Diamond

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The Koh-i-Noor set in the Maltese Cross at the front of the Crown of Queen Elizabeth

The Koh-Noor means “Mountain of Light” from Persian, is a 105.6ct diamond that was once the largest known diamond in the world.  Its original weight was estimated to be 787ct.    The Koh-i-Noor originated at Kollur, Guntur district in the state of Andhra Pradesh in India, one of the world’s earliest diamond producing regions. This region was the only known source for diamonds until 1730 when diamonds were discovered in Brazil. The term “Golconda” diamond has come to define diamonds of the finest white color, clarity and transparency. They are very rare and highly sought after.

It has belonged to various Hindu, Mughal, Persian, Afghan, Sikh and British rulers who fought bitterly over it at various points in history and seized it as a spoil of war time and time again.  It was finally seized by the East India Company and became part of the British Crown Jewels when Queen Victoria was proclaimed Empress of India in 1877.

The origin of the diamond is unclear, although several rumors exist.

The Hindu legends date the Koh-i-Noor back to 5000 years when the ancient maharajahs who owned it successively believed that the ‘giant gem’, was endowed with great magical powers.  Its original Hindu name was Semantik Mani but it was renamed in 1739 by the Persian emperor Nadir Shah as the Koh-i-Noor or Mountain of Light.

Nadir Shah was murdered and the Koh-i-Noor was passed on from one Muslim ruler to another until in 1813, it was wrested out of Muslim hands into the possession of the Sikh ruler Ranjit Singh, also known as the Lion of Punjab.  After Ranjit Singh’s death, the Punjab was annexed by the British East India Company which later presented it to Queen Victoria.

Today the Koh-i-Noor sits peacefully in the crown of Queen Elizabeth, the Queen Mother, in the Jewel House in the Tower of London.  The two legends behind the Koh-i-Noor are that the owner of this Diamond will rule the world and that it must never be worn by a man.  Three queens of England have owned it and no British King had ever worn it.


Rare Blue Diamond Sold

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Posted: April 24, 2016

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A rare blue diamond has gone up for sale and smashed auction records in Asia.

The 10.10 carat rock, named the De Beers Millennium Jewel 4, is the largest oval-shaped, fancy vivid blue diamond to ever appear at auction world.

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The ‘De Beers Millennium Jewel 4’ went on auction as part of a 270 lot ‘Magnificent Jewels and Jadeite’, sale by auction house Sotheby’s on April 5 in Hong Kong.

Billed by Sotheby’s as “yet another wonderful collecting opportunity for connoisseurs worldwide”, it was sold for $31.8 million – which makes it the most expensive gemstone to be sold at an auction in Asia.

Blue diamonds are considered to be one of the rarest of gems, making up just a small percentage of all diamonds harvested worldwide.

But while this blue beauty has broken all records for sales of the gem in Asia, its value still falls short of the world’s most expensive diamond.

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That title went to the 12.03 carat “Blue Moon” diamond, sold in Geneva, Switzerland, to a Hong Kong billionaire for his seven-year-old daughter in November 2015 for $48.4million.

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The auction included some of the world’s rarest colored diamonds.

Repost from CNN: http://edition.cnn.com/

 

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