India's polished exports raised for the first time this year in September, up 11 % from 2008, to $1.76 billion, as per the data published by the Gem & Jewellery Export promotion Council (GJEPC). By means of volume, exports rose 12% to 4.613 million carats as average prices were downward 1 % to $381.88 per carat. Polished imports cut down 18 % to $584.9 million as well as net polished exports, on behalf of the excess of exports over imports, rose 35 % to $1.2 billion.
Rough imports turned down 25 % to $689.56 million and by volume, imports cut down 21 % to 11.918 million carats. The average price of rough imports fell 6 % to $57.86 per carat. Rough exports progressed1 % to $73.3 million and net rough imports, or imports less exports, diminished 27 % to $616.3 million.
India's September net diamond account, evaluating total exports of polished and rough less total imports, progressed to $560.4 million, equated with $23.7 million one year ago.
For the year to date from beginning to end September, India's polished exports came down 22 % to $9.59 billion, while polished imports degenerated 12 % to $5.07 billion. Net polished exports refused 30 % to $4.52 billion.
Rough imports diminished 46 % to $4.52 billion and rough exports were downward by 17 % to $524.6 million. Net rough imports fell 49 % to $3.99 billion. India's net diamond account for the primary nine months of the year was $521 million, match up to with negative $1.33 billion a year earlier.
Showing posts with label diamond facts. Show all posts
Showing posts with label diamond facts. Show all posts
Monday, October 26, 2009
Tuesday, September 1, 2009
Oval-Cut Diamond.
‘An Oval cut diamond has an elliptical silhouette when observed from the top’.
The oval cut is predominantly fine-looking shape and if well balanced gives immense scintillation and flames. A well cut oval diamond can be approximately as dazzling as a well cut Brilliant or round shaped diamond as the angles for cutting are nearer to that of a brilliant cut diamond.
Meant for the Oval, the proportion of the length to the width must be about 1.5:1. If it is much greater than that you will see a shady area. This shady area is commonly called a bow tie effect, "undesirable". If the proportion is much less then 1.5:1, the stone looks like a deformed round. A well cut oval stone can be nearly as dazzling as a well cut round brilliant shape, the angles are nearer to ultimate for the utmost optical effect that well cut diamonds can produce. Trust your eye to referee the cut, if an oval shape looks inert in natural light odds are it's a very feebly cut stone. Reside with lower sixties in depth for this cut.
For depth as well as table spec on oval cut look to a diamond that is in the mid-sixties to lower seventies in intensity and a table size in the upper fifties to upper sixties for a chock-a-block and brilliant effect. The distance end to end is somewhat grave here, and distinct than the round diamond cut in a wider and fuller range for exquisiteness in this most elegant cut. The table sizes for instance will be seen to go over a fairly wide range, and in this range have a preference of the lower to mid sixties table size for smaller or larger seem to dumb down the luminosity and blaze. The crown facets need to signify enough proportion to fully slot in for that vivid and active look. Diamond Exotica personally inspect all diamonds we sell, and in the fancy shapes that is grave, so we take the moment and do it right. Others want to sell off a list, we be capable of to personally confirm that the diamond you take delivery of will be the dream diamond you always sought after.
Nevertheless adequate of that, words mean nothing; certificate, references and cost mean the whole thing. Just keep in mind to bookmark our page and locate your perfect diamond is a snap!
The solution to a gorgeous engagement ring is to create with a stunning diamond and that is our area of expertise.
Also check Diamond Blog
Thursday, August 27, 2009
Shapes of Diamonds
Round BrilliantRound diamonds are the most well-liked of all the shapes, possibly because their circular proportions display the most "fire" and reflect more light back to the observer than any other shape. Round diamonds require that more rough be removed through cutting and polishing than with other shapes. The combined popularity of round diamonds and the important weight loss during cutting are the two main causal factors to the relatively higher price of these stones.
Princess
The Princess cut is a square cut with sharp ends. It has extremely good fire and a high degree of brilliance. The princess cut utilizes most of the unique shape of the rough diamond and the weight loss from cutting is low. As a consequence, its price is typically more attractive than a comparative round cut with the same weight.
Eme
rald cutsEmerald cuts are smooth and stylish. The Emerald cut is rectangular by means of cut corners. It is a step cut - its facets being broad with flat planes like the steps of a stair. Higher quality Emerald cuts are favored because its cut makes inclusions and lower color grades more obvious than with other cuts. The emerald cut diamond can be totally stunning. Because of its long lines, it tends to be less burning than a "round brilliant" cut, but it also tends to have broader, more dramatic flashes of light.
Marquise
The Marquise cut is boat shaped and is a difference of the round brilliant cut diamond. Marquise cuts are often chosen by women who wish to show an independence of style. Its elongated form can make the illusion of longer, narrower fingers.
Radi
antThis is a customized or combination cut - a brilliant cut square or rectangle shaped diamond with clipped-off corners similar to the emerald cut. It melds the stylishness of the emerald cut diamond with the brilliance and sparkle of the round diamond.
Pear
The Pear cut is a tear-drop shape and is a disparity of the round brilliant cut diamond. This attractive diamond is also very well-suited to pendants and earrings. Lots of the largest stones ever discovered have been cut and faceted into wonderful pear-shapes.
Heart
shapeThe ultimate symbol of love, the romantic Heart shape is a difference of the round brilliant cut diamond. This ultimate symbol of romance is basically a pear-shaped diamond with a cleft at the top. The ability of the cutter determines the beauty of the cut. Appear for a stone with a yet shape and a well-defined outline.
Oval
The Oval cut is egg-shaped in shape and is a variation of the round brilliant cut diamond. The oval shaped diamond gives a pleasing delusion of length to the finger and hand, and is well-liked among women with small hands or short fingers. It can also emphasize long, slender fingers.
Assc
herThe Asscher cut is an alternative of the emerald cut and provides a uniquely regal and elegant look to its wearer. Its art-deco styling combines old-world charm with contemporary cutting and faceting techniques to create a dazzling example of brilliance.
Tuesday, August 4, 2009
Diamond jewelry For Special Touch
Diamond Jewelry Adds Special Touch To Your Personality
For centuries diamonds are considered as special and somebody who likes and wear it is seems as a person of style and sophistication. You are sourcing for one of those because your wedding day is close. You have to be impressive and beside the beautiful dress and other outfits wedding jewelry also must be as much beautiful. You know that diamonds are one of best jewelry choices and you know diamonds will add you a special touch to feel like a princess. And you are a princess to your prince! Your choice is beautiful and on wedding day everybody will be amazed with your diamond jewelries.
Whether you decide to have a diamond ring, necklace, bracelets or earrings as a single or couple two of diamond pieces you want mistake because almost every woman prefers diamonds, and how wouldn’t. Diamonds sparkle like stars and take breath to everybody. This kind of jewelry will show that you are a person of style and sophistication. As for women diamonds are also attractive for men and besides diamonds rings are unique because they fit perfectly both men and women. You may consider you as a very happy woman if your wedding or engagement ring is going to be diamond because not everybody can afford diamond jewelry. With a diamond engagement or wedding ring your prince shows all his love to you.
Diamond jewelry is available in many shapes, designs and colours. Sometimes diamonds were coluorless but in joy of many diamonds lovers nowadays it is available in deep blue, rich reds, yellows, greens and many more so your choice is huge. Diamond jewelry is always in fashion, and there no time that will change that fact. That kind of jewelry is absolutely fabulous in anytime, anywhere in any shape, design end colour.
Diamond rings are considered as a great gift and are matter of status and style.
As diamond rings there are also diamonds bracelets which are elegant, too. It fits perfectly to the look whether men or women. If it is going to be your wedding choice that will be very precious lifetime investment and also it will be your lifetime memory.
Besides, there are diamond necklaces which are very beautiful, too. Having it on your neck you’ll look amazing, very stylish and elegant.
So if you are a diamond lover be in touch with diamond trend and provide yourself wedding diamond jewelry in kind you like the most. It will inspire your soul and your feelings letting you feel special on your most important day. No doubt that diamond jewelry is great choice for everybody.
Tuesday, July 28, 2009
Facts About DIamonds
Diamond facts
* All diamonds are at least 990,000,000 years old. Many are 3,200,000,000 years old (3.2 billion years)
* Diamonds are formed deep within the Earth: between 100 km and 200 km below the surface.
Diamonds form under remarkable conditions!
o The temperatures are about 900 - 1300 C in the part of the Earth's mantle where diamonds form
o The pressure is between 45 - 60 kilobars (kB)
+ 50 kB = 150 km = 90 miles below the surface
+ 60 kB = 200 km = 120 miles below the surface
Diamonds are carried to the surface by volcanic eruptions.
The volcanic magma conduit is known as a kimberlite pipe or diamond pipe. We find diamonds as inclusions in the (rather ordinary looking) volcanic rock known as kimberlite.
NOTE: The kimberlite magmas that carry diamonds to the surface are often much younger than the diamonds they transport (the kimberlite magma simply acts as a conveyer belt!).
* Diamond is made of carbon (C), yet the stable form (polymorph) of carbon at the Earth's surface is graphite.
graphit1.png
* To ensure they are not converted to graphite, diamonds must be transported extremely rapidly to the Earth's surface.
It is probable that kimberlite lavas carrying diamonds erupt at between 10 and 30 km/hour (Eggler, 1989). Within the last few kilometers, the eruption velocity probably increases to several hundred km/hr (supersonic!).
* Diamond is the hardest material
Diamond is the hardest gem on MOHS harness scale and graphite (also made from carbon atoms) is the softest !! Given that both diamond and graphite are made of carbon, this may seem surprising.
The explanation is found in the fact that in diamond the carbon atoms are linked together into a three-dimensional network whereas in graphite, the carbon atoms are linked into sheets with very little to hold the sheets together (thus the sheets slide past each other easily, making a very soft material).
Diamonds occur in two general types of deposits world wide:
* volcanic pipes, also known as kimberlite pipes
* alluvial, or placer, deposits, which were formed by the erosion of diamond pipes over millions of years.
The earliest productive mines were in the Golconda region of India, particularly along the Kristna River. After 1725 this mining district was gradually eclipsed in importance by the diamond deposits of Brazil. Diamonds were first mined there along the Jequitinhonha River, in the Diamantina area of the state of Minas Gerais.
In 1867 a 21-carat stone was discovered on the banks of the Orange River near Hopetown, South Africa. A great diamond rush started, and new deposits were discovered that were more productive than any the world had ever known. Another major diamond resource was developed in the 1950s in the Yakutia region of the Soviet Union. By the 1980s the Yakutia and South African regions and the country of Zaire dominated the world's diamond market. The mineral has also been found in smaller amounts in numerous other places. In the United States the leading producers include Arizona, Nevada, and Montana, although the largest gemstones have been found in an eroded volcanic pipe in Pike County, Ark.
zaire.jpg rough diamond1.jpgbighole-south africa-diamond mine.png diamond mine yakutia.jpg rough- in hand.jpg diamond sorting.jpg dede-beim schleifen.png
For many years, microscopic diamonds have occasionally been noted in meteorites; they were attributed to high-speed collisions in space or with the Earth. In 1987, however, following the discovery of many more such diamonds, the theory was developed that they are the product of ancient supernova explosions of giant stars.
In recent years, diamonds have been found in unusual metamorphic rocks that were subjected to very high temperatures and pressures.
HOW RARE ARE DIAMONDS?
· How many grams do you need to mine to get 5 grams of diamonds?
(5g/1000 kg) @ 1000 g/kg = 5 g /1,000,000 g!
BUT only 20 % are gem quality (80 % of these are sold in a 'managed selling environment') and the remainder are used for industrial purposes (this material is known as 'bort' or 'carbonado' (carbonado is finer)).
CHARACTERISTICS OF DIAMOND:
· Hardness = 10
· Crystal System = cubic
· This is what crystals look like before they are faceted: note their natural octahedral shape!
Uncut diamonds are also found in cubic forms
· Diamond has four good cleavages, thus diamonds tend to cleave on impact
· Other diagnostic properties.
Other issues: Treatment, simulants, synthetics
(1) TREATMENTS:
* (a) filling of cracks
Surface cracks and cleavages reaching the surface: often with a glass-like material
Identification: optical microscope examination:
+ =greasy appearance
+ =flash effect
+ =bubbles
Problem: Filling does not always resist polishing and cleaning
* (b) drilling of inclusions
+ Drilling inclusions involves use of a laser.
Solutions can be poured into the resulting "hair-width" diameter hole to bleach colored inclusions.
* (c) irradiation
Irradiation is used to change the color of the diamond. A common color produced by irradiation is green.
Early attempts: beginning of 20th Century: diamonds exposed to radium - the problem was that the diamonds remained radioactive!! However, modern irradiation treatments do not produce radioactive stones.
Irradiation involves the use of devices such as:
o (1) linear accelerators
o (2) gamma ray facilities
o (3) nuclear reactors
Detection of irradiation treatment:
Electron irradiation only changes the surface of the stone. Thus, it produces a concentration of color where the gemstone is thin. For example, electron irradiation produces a color concentration at the culet or keel line of the faceted gem
(2) SIMULANTS
Simulants - simulate the appearance of diamond
The distinction between a synthetic diamond (man-made diamond consisting of carbon atoms arranged in the typical diamond structure) and a diamond simulant (not a carbon compound with the diamond structure) is VERY important!!
In order of increasing R.I., the most common simulants are:
1. YAG = yttrium aluminum garnet
2. GGG = gadolinium gallium garnet
3. CZ = cubic zirconia
4. Strontium titanate
5. diamond.
This rhyme can be used to memorize the common diamond simulants in the above order:
You go crazy staring at diamonds.
Again: Simulants (look alsikes) differ from synthetics (synthesized by humans!) !!!!
Simulants are distinguished from diamonds using measurement or observation of various properties, such as:
o R.I.
o "Read through effect"
o Dispersion
o Hardness
o Specific Gravity
o Reflection pattern
o Shadow patterns
Note: not all diamond simulants have been around for the same length of time!
(3) SYNTHESIS (Details on gem synthesis)
Synthetic diamonds are often yellowish in color (rarely used for gem purposes, more commonly used as diamond grit for industrial purposes. Modern synthesis of thin film diamond has other industrial applications).
A 5 mm diamond (0.5 carat) takes over a week to grow. Synthesis requires:
* high pressure
* high temperature
* a special apparatus
Synthetic diamonds can sometimes be distinguished from natural diamonds by the presence of flux inclusions (Ni, Al or Fe).
Also see Other Blog on Diamond: Diamonds Exotica
* All diamonds are at least 990,000,000 years old. Many are 3,200,000,000 years old (3.2 billion years)
* Diamonds are formed deep within the Earth: between 100 km and 200 km below the surface.
Diamonds form under remarkable conditions!
o The temperatures are about 900 - 1300 C in the part of the Earth's mantle where diamonds form
o The pressure is between 45 - 60 kilobars (kB)
+ 50 kB = 150 km = 90 miles below the surface
+ 60 kB = 200 km = 120 miles below the surface
Diamonds are carried to the surface by volcanic eruptions.
The volcanic magma conduit is known as a kimberlite pipe or diamond pipe. We find diamonds as inclusions in the (rather ordinary looking) volcanic rock known as kimberlite.
NOTE: The kimberlite magmas that carry diamonds to the surface are often much younger than the diamonds they transport (the kimberlite magma simply acts as a conveyer belt!).
* Diamond is made of carbon (C), yet the stable form (polymorph) of carbon at the Earth's surface is graphite.
graphit1.png
* To ensure they are not converted to graphite, diamonds must be transported extremely rapidly to the Earth's surface.
It is probable that kimberlite lavas carrying diamonds erupt at between 10 and 30 km/hour (Eggler, 1989). Within the last few kilometers, the eruption velocity probably increases to several hundred km/hr (supersonic!).
* Diamond is the hardest material
Diamond is the hardest gem on MOHS harness scale and graphite (also made from carbon atoms) is the softest !! Given that both diamond and graphite are made of carbon, this may seem surprising.
The explanation is found in the fact that in diamond the carbon atoms are linked together into a three-dimensional network whereas in graphite, the carbon atoms are linked into sheets with very little to hold the sheets together (thus the sheets slide past each other easily, making a very soft material).
Diamonds occur in two general types of deposits world wide:
* volcanic pipes, also known as kimberlite pipes
* alluvial, or placer, deposits, which were formed by the erosion of diamond pipes over millions of years.
The earliest productive mines were in the Golconda region of India, particularly along the Kristna River. After 1725 this mining district was gradually eclipsed in importance by the diamond deposits of Brazil. Diamonds were first mined there along the Jequitinhonha River, in the Diamantina area of the state of Minas Gerais.
In 1867 a 21-carat stone was discovered on the banks of the Orange River near Hopetown, South Africa. A great diamond rush started, and new deposits were discovered that were more productive than any the world had ever known. Another major diamond resource was developed in the 1950s in the Yakutia region of the Soviet Union. By the 1980s the Yakutia and South African regions and the country of Zaire dominated the world's diamond market. The mineral has also been found in smaller amounts in numerous other places. In the United States the leading producers include Arizona, Nevada, and Montana, although the largest gemstones have been found in an eroded volcanic pipe in Pike County, Ark.
zaire.jpg rough diamond1.jpgbighole-south africa-diamond mine.png diamond mine yakutia.jpg rough- in hand.jpg diamond sorting.jpg dede-beim schleifen.png
For many years, microscopic diamonds have occasionally been noted in meteorites; they were attributed to high-speed collisions in space or with the Earth. In 1987, however, following the discovery of many more such diamonds, the theory was developed that they are the product of ancient supernova explosions of giant stars.
In recent years, diamonds have been found in unusual metamorphic rocks that were subjected to very high temperatures and pressures.
HOW RARE ARE DIAMONDS?
· How many grams do you need to mine to get 5 grams of diamonds?
(5g/1000 kg) @ 1000 g/kg = 5 g /1,000,000 g!
BUT only 20 % are gem quality (80 % of these are sold in a 'managed selling environment') and the remainder are used for industrial purposes (this material is known as 'bort' or 'carbonado' (carbonado is finer)).
CHARACTERISTICS OF DIAMOND:
· Hardness = 10
· Crystal System = cubic
· This is what crystals look like before they are faceted: note their natural octahedral shape!
Uncut diamonds are also found in cubic forms
· Diamond has four good cleavages, thus diamonds tend to cleave on impact
· Other diagnostic properties.
Other issues: Treatment, simulants, synthetics
(1) TREATMENTS:
* (a) filling of cracks
Surface cracks and cleavages reaching the surface: often with a glass-like material
Identification: optical microscope examination:
+ =greasy appearance
+ =flash effect
+ =bubbles
Problem: Filling does not always resist polishing and cleaning
* (b) drilling of inclusions
+ Drilling inclusions involves use of a laser.
Solutions can be poured into the resulting "hair-width" diameter hole to bleach colored inclusions.
* (c) irradiation
Irradiation is used to change the color of the diamond. A common color produced by irradiation is green.
Early attempts: beginning of 20th Century: diamonds exposed to radium - the problem was that the diamonds remained radioactive!! However, modern irradiation treatments do not produce radioactive stones.
Irradiation involves the use of devices such as:
o (1) linear accelerators
o (2) gamma ray facilities
o (3) nuclear reactors
Detection of irradiation treatment:
Electron irradiation only changes the surface of the stone. Thus, it produces a concentration of color where the gemstone is thin. For example, electron irradiation produces a color concentration at the culet or keel line of the faceted gem
(2) SIMULANTS
Simulants - simulate the appearance of diamond
The distinction between a synthetic diamond (man-made diamond consisting of carbon atoms arranged in the typical diamond structure) and a diamond simulant (not a carbon compound with the diamond structure) is VERY important!!
In order of increasing R.I., the most common simulants are:
1. YAG = yttrium aluminum garnet
2. GGG = gadolinium gallium garnet
3. CZ = cubic zirconia
4. Strontium titanate
5. diamond.
This rhyme can be used to memorize the common diamond simulants in the above order:
You go crazy staring at diamonds.
Again: Simulants (look alsikes) differ from synthetics (synthesized by humans!) !!!!
Simulants are distinguished from diamonds using measurement or observation of various properties, such as:
o R.I.
o "Read through effect"
o Dispersion
o Hardness
o Specific Gravity
o Reflection pattern
o Shadow patterns
Note: not all diamond simulants have been around for the same length of time!
(3) SYNTHESIS (Details on gem synthesis)
Synthetic diamonds are often yellowish in color (rarely used for gem purposes, more commonly used as diamond grit for industrial purposes. Modern synthesis of thin film diamond has other industrial applications).
A 5 mm diamond (0.5 carat) takes over a week to grow. Synthesis requires:
* high pressure
* high temperature
* a special apparatus
Synthetic diamonds can sometimes be distinguished from natural diamonds by the presence of flux inclusions (Ni, Al or Fe).
Also see Other Blog on Diamond: Diamonds Exotica
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