Showing posts with label shape. Show all posts
Showing posts with label shape. 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.

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.

How To Determine Diamond Prices

Pricing most products is quite easy. Determine how much it costs to make the item, how much it costs to market that item, and then mark it up by 15 – 30% or more. Simple, right? Well, pricing diamonds isn’t quite that simple. There are many factors that are considered when diamonds are priced.

Diamond prices are determined first by adding the cost of the rough diamond, the cost of cutting the diamond, and all other costs necessary to turn the rough diamond into a marketable diamond. Depending on the importance of the diamond, an independent company may be called in to certify the grade of the diamond based on colour, cut, clarity, and weight.

Before reaching the retailer, the diamond must travel from the mine, to the cutter and polisher, to the independent grading company, and then to the primary market. Once it has reached the primary market, it will be purchased by diamond dealers and wholesalers, and from there it will be sold to retailers. The diamond becomes more expensive each time it changes hands, until it finally reaches a retailer, where the price is raised a bit more.

The value of a diamond is based on what the diamond will sell for in the market place through a retailer. As you can see, the earlier you can purchase a diamond in the process, the lower the cost of the diamond will be – but not the value.

If you own a diamond, and you have no idea how much it is worth, you can have it appraised, but the appraisal may not be accurate. You will be better off obtaining a certificate through GIA – Gemological Institute of America. With the information on this certificate, you can use a diamond price guide to accurately determine what your diamond is worth.

There are also many diamond price calculators available on the Internet, and many diamond dealers use these as well. You will realize that before you can accurately price a diamond, without a Diamond Grade Report, you need to know quite a bit about diamonds, such as different cuts, clarity, color, and weight – and how each of those aspects adds to the value of a diamond, or decreases the value of the diamond as the case may be.

Again, you will be better off if you get a Diamond Grading Report on the diamond, and use that information to look up the price in one of the guides that the diamond cutting industry uses. This will give you the most accurate value of the diamond in your possession, or of the diamond you are considering to purchase.

Quick Guide to Selecting Diamonds

Diamonds are graded for certification by laboratories using grading criteria. Four of these criteria are critical to understand when making a diamond purchase or investment. Known as the “Four C’s”, these criteria are: color, cut, clarity and carat.

Colour
Color is the result of the composition of a diamond and it does not change. When a jeweler is describing the color of a diamond they are referring to the presence or absence of color in white diamonds. Because a diamond with no color allows maximum light to pass through, colorless diamonds are preferred for their sparkle.

Read more on Diamond Colour.

Cut
Cut refers to a diamonds reflective quality. Most diamonds are cut with 58 facets. The brilliance of diamonds is heavily dependent on the cut. The different angles and the finish of a diamond determine its ability to reflect light and cause its brilliance and fire.

Remember that the cut of a diamond can have an impact on its durability as well as its beauty. Some cutting faults can make a diamond prone to breakage. A diamond that is cut too thin can also cause light to leak out of the back and the diamond will lose some of the sparkle and appear not to shine. So, as you can see the cut is probably the most important of the Four C’s.

Read more on Diamond Cut.

Clarity
During the formation process, inner flaws, or inclusions occur in most diamonds. The number and size of these inclusions determine what is referred to as the clarity of a diamond. Diamonds that are clear create more brilliance and therefore are rarer and highly priced. To be considered “flawless”, a diamond must have no surface or internal imperfections visible upon being viewed by a skilled diamond grader using 10 power magnifications.

Read more on Diamond Clarity.

Carat
Carat is the unit of weight by which diamonds are measured. One carat is equal to 200 milligrams. A carat is divided into 100 segments called points.

Read more on the carat weight.

When you go to the store to make that all important diamond purchase, do not be shy! Ask questions, get the answers needed to make an informed purchase. Shopping for certified diamonds enables you to make an informed selection. Knowing the “four C’s” allows you to comparison shop and purchase the best diamond at a fair price. But, before making a purchase, shop around and decide what shapes and styles really appeal to you. Enjoy your diamond for years to come!

4Cs - Diamond Cut

There are many different cuts of diamonds to choose from. The cut essentially refers to the shape and proportion that the diamond is cut into and this has a great impact on how the much the diamond sparkles.

Diamond Anatomy, Shapes and Cuts
The most popular cuts are heart, marquise, oval, pear, princess, round, trillion, and emerald cuts, with the round cut being the most common of all:
The shape has an impact on how much the diamond sparkles, but the actual cutting itself – when the diamond cutter actually cuts the diamond into a particular shape – also matters a great deal. If the diamond is poorly cut, it will have poor proportions and symmetry and will lose its sparkle, which is essentially based on the amount of light being reflected to the viewer's eyes. The proportion of a round diamond includes its gridle diameter and thickness, table width, crown height, pavilion depth, and culet.

Common cutting problems include a missing or off center culet, misalignment, a diamond that is too thick or too thin, cracks, or broken culets.

Choose Shape First, Followed By Cut
It is almost impossible to manually measure the proportions of diamonds in typical jewellery stores because they are either too small (in carat weight) or already set into jewellery pieces. Therefore when shopping, you should of course choose the shape that you like the best, and then look at several different diamonds of that shape to find the one with the best cut – the one that sparkles the most, in all types of lighting.