Showing posts with label rough diamond. Show all posts
Showing posts with label rough diamond. Show all posts

Famous Diamonds

The Hope

Among the most well known diamonds is the Hope. This 45.52 carat steel blue diamond is currently on display at the Smithsonian. The legends of the ill-fortune and curse bestowed on the possessor of the Hope Diamond are many. This diamond was donated to the Smithsonian in 1958. The Hope was originally a rather flat, blocky 110-carat rough.


 
Dresden Green

 The Dresden Green stands out among the natural colored diamonds. It is the largest green diamond in the world weighing 40.70 carats. This diamond is historic, large and has a natural green color with a slight blue overtone. These facts make it virtually priceless.


 
Conde Pink

The Conde Pink is a pear shaped and weighs 9.01 carats. This pink diamond was once owned by Louis XIII.









Tiffany Yellow

The Tiffany Yellow diamond a beautiful canary-yellow octahedron weighing 287.42 in the rough carats discovered in either 1877 or 1878 in South Africa. The gem after cutting boasts the extraordinary weight of 128.54 carats. And until recently, was the largest golden-yellow in the world.



Mountain of Light

The Koh-I-Noor (Mountain of Light) is now among the British Crown Jewels. This diamond weighs 105.60 carats. First mentioned in 1304, it is believed to have been once set in Shah Jehan‘s famous peacock throne as one of the peacocks eyes.



The Agra

The Agra is graded as a naturally colored Fancy Light Pink and weighs 32.34 carats. It was sold for about 6.9 million in 1990. Since this sale, it has been modified to a cushion shape weighing about 28.15 carats.





 Transvaal Blue

The Transvaal Blue is pear cut. This blue diamond weighs 25 carats. It was found in the Premier Diamond Mine in Transvaal, South Africa.









 Great Chrysanthemum

The Great Chrysanthemum was discovered in the summer of 1963, in a South African diamond field. This 198.28 carat fancy brown diamond appeared to be a light honey color in its rough state. However, after cutting, it proved to be a rich golden brown, with overtones of sienna and burnt orange.



Taylor-Burton

The Taylor-Burton Diamond is a pear-shaped 69.42 carat diamond. Cartier of New York purchased this diamond at an auction in 1969 and christened it "Cartier." The next day Richard Burton bought the diamond for Elizabeth Taylor. He renamed it the "Taylor-Burton”. In 1978, Elizabeth Taylor put the diamond up for sale. Prospective buyers had to pay $2,500 each to view the diamond to cover the costs of showing it. Finally, in June of 1979, the diamond was sold for nearly $3 million dollars.

The One In A Million

When you walk into a jewellery store and see all the diamonds in all of the various settings that are for sale, it is difficult to realize that diamonds are indeed rare. Most people don’t even stop to consider how that diamond came to be sitting in that jeweller’s case! There is quite a bit of work that is done before a diamond is ready to sell to the general public!

For every one million diamonds that are mined, only one will be found that is a quality one carat diamond. In order to find a two carat diamond, about five million diamonds must be mined. More than two hundred tons of ore must be mined to find one small diamond, and even then, more than 80% of the diamonds that are mined are only good for industrial use, such as diamond drill bits.

So, the next time you visit your local jewellery store, ask to see the one carat diamonds. You should look at this diamond with new appreciation – knowing that it truly is one in a million!

Fancy and Coloured Diamonds

The most famous diamonds in the world are coloured, or fancy, diamonds. The Tiffany Diamond, which is yellow, and the Hope Diamond which is blue, are coloured diamonds. Coloured diamonds vary from red, green, purple, violet, orange, blue and pink – and most shades between. Fancy colour shades vary from faint to intense.

Treated and Synthetic Diamonds
Fancy coloured diamonds are all the rage these days. Gemologists have developed new ways to create versions that are affordable for the average person - by treating less desirable diamonds. These less desirable diamonds are treated with irradiation followed by intense heat. This turns brown and yellowish diamonds into beautifully coloured diamonds that you can afford. This produces stunning greens, blues, yellows, reds, purples and other colours. These colours are considered permanent, but there is a possibility they could change during repairs if a high heat is used.

Treatments like irradiation make it possible for more people to own these vividly coloured diamonds. Most natural coloured diamonds are rare and also extremely expensive. When shopping for coloured diamonds you need to assume that any affordable fancy colour diamond has been treated. Ask about the stone's origin and request to view a lab certificate to verify authenticity.

Synthetic coloured diamonds are another option if owning a coloured diamond is something you desire but cannot quite afford. They are real diamonds, but they are created in a lab.

Natural Diamonds
Natural fancy colour diamonds get their colouring from different trace elements present in the stones, such as nitrogen, which produces a yellow diamond. Diamonds can be coloured by exposure to radiation during its creation. An example of a diamond affected by radiation is the green coloured diamond.

Another way that a natural coloured diamond gets colour is by its inclusions. Regarded as flaws and undesirable in a colourless diamond, inclusions give unique tones and brilliant flashes of colour in a fancy colour diamond. Remember that natural fancy coloured diamonds are very expensive, any coloured diamond labeled to be sold as natural should be accompanied by a certificate from a respected grading lab.

Coloured diamonds have an amazing financial track record. The value has never decreased on wholesale level in more than 30 years. Blue and pink diamonds have doubled every 5 years of a strong economy. In the 1970’s you could have bought a very high quality blue diamond for about 50K and today the very same stone would be worth between 2 and 3 million.

How Are Diamonds Mined?

We seldom think about how the diamonds we wear came to us. Natural diamonds, as opposed to synthetic diamonds or fake diamonds, are mined from the earth. There are currently two methods of mining diamonds: Pipe Mining and Alluvial Mining.

Pipe Mining
When pipe mining is used, the diamonds are extracted from the earth through volcanic pipes. These are not man-made pipes - they are natural pipes in the ground. Shanks are put into the ground next to the pipes, and tunnels are driven into the deepest parts of the pipe. The diamonds are not sorted out at the mine. Instead, huge rocks that are full of diamonds are brought out of the mine and moved to a screening plant for separation.

Alluvial Mining
The Alluvial mining method is done in riverbeds and on beaches. Walls are built to hold back the water and the sand on the bank or beach. The sand is moved with a bulldozer until the level of earth that diamonds can be found in is reached. Again, the diamonds are not sorted here. Instead, the sand that contains the diamonds is bulldozed into trucks, and taken to screening plants.

At the diamond screening plants, natural rough diamonds are extracted from the rocks and earth, and then undergo cutting and polishing, before finally becoming the diamonds we see on jewellery.

How Are Diamonds Cut?

In their most natural form, diamonds are, well, quite ugly. They have no luster or shine, and in fact, look like nothing more than broken glass. A diamond must be cut, and then polished before it actually becomes a thing of beauty.

Planning and Marking
A rough diamond is first examined by a planner to determined how it should be cut to yield the best value. The planner takes into consideration of the grain and crystal structure of the diamond to mark positions where it would be cleaved or sawed by the diamond cutters.

Cleaving
Large diamonds are separated into smaller pieces, by a process known as cleaving, that are suitable for further sawing. Cleaving is also done to quickly remove large unwanted pieces (usually areas with blemishes and other imperfections) from the rough diamond. This process is important as a wrong split will ruin the diamond and reduce the value of the diamond drastically.

The cleaver carefully cut grooves into the diamond at locations marked by the planner with another diamond. He then splits the diamond along the grooves with a mallet and a metal wedge. The diamond is now ready for sawing.

Sawing
Sawing shapes the diamond into various shapes such as heart, square, or the common round shapes. A circular disk saw is used to cut it down to shape. The cutting edge of the saw is initially coated with diamond dust in order to start the first few cuts. After the first few cuts, the cutting edge of the saw will coat itself with diamond dust from the diamond that is being cut. This maintains the hardness of the saw's cutting edge.

Girdling
The diamond is further shaped and its freshly cut edges are rounded by girdling. The diamond is mounted on a lathe and another diamond is used to grind it into shape.

Faceting
A diamond lapper or scaife that is coated with diamond dust is used to cut the facets. Faceting is the final and one of the most important steps in diamond cutting where the facets of a diamond is cut. The quality of the faceting that is being done will determine the brillance and fire of the diamond. Each facet of the diamond must be carefully cut into the geometrical shapes that allow maximum refraction and reflection of incident light.

Polishing
Polishing is the final step to transform a rough diamond into a diamond that is ready for sale. A diamond lapper is used, but with a different, finer lapping disk. The diamond is then finally ready for certification grading and sales or further setting into jewellery.

Rough and Dirty Diamonds

A dirty diamond is one of two things: a rough diamond, or a diamond that hasn’t been cleaned in a while. Rough diamonds are uncut and unpolished – hence, they are dirty. But that type of dirty diamond will soon be cut and polished and sitting in a beautiful jewel box in a display case. Then someone will purchase it, and before long, it will become a dirty diamond once again.

Diamonds become dirty. When you wash your hands with a diamond ring on, soap scum clings to it. When you put on hand lotion, it gets grease on it. Shower with your diamond earrings or necklace, and again, you get soap scum. In one short day, your brand new diamond could be dirty!

Purchase an ultrasonic jewellery cleaner the same day that you purchase your diamond jewellery, and use it every single day, without fail. The clarity of the diamond changes when the diamond is dirty – it loses its sparkle. By taking one minute each day to clean your diamond jewellery, you can avoid this, and your diamonds will never be dirty again!