Clarity and Carat

The most common usage of diamonds today is as gemstones used for jewelry. When buying a diamond you should always have four factors (four Cs) in the mind. These four Cs are Cut, Color, Clarity and Carat. Majority of gem diamonds is traded on the wholesale market based on single values for each of these 4 factors. To set expected price range you need to know all four factors and consumers that are purchasing individual diamonds are often advice to use the 4 Cs in order to buy diamond that is just right for them. However although main characteristics of each diamond are described with four Cs you also need to consider some other characteristics, for instance presence of fluorescence of individual diamond and even history of the diamonds.Diamond cutters for instance prefer more princess cut style than the round brilliant because much less material is wasted in princess cut. Some cuts even include extra facets, although their improvement value compared to Tolkowsky's model stays doubtful.

Great Chrysanthemum Diamond

The Great Chrysanthemum Diamond is a diamond measuring 104.15 carats (20.830 g) with a Pear-Shaped Modified Brilliant Cut, rated in colour as Fancy Orange-Brown and I1 clarity by the Gemological Institute of America. The diamond's origins are in South Africa, where it was bought by the jeweler Julius Cohen as a 198.28 carat (39.656 g) rough in 1963. After buying it, Cohen returned to New York where he had it cut into its distinctive pear shape by S&M Kaufman. Because of its colouring similarities to the brown chrysanthemum, it was named after that flower.
The Great Chrysanthemum has been shown in a number of diamond exhibits throughout the United States. In 1965, the Chrysanthemum was named a winner of one of the Diamonds International Awards and was placed on display in the Rand Easter Festival in Johannesburg, South Africa. Julius Cohen later sold the diamond to an unknown and reputedly foreign buyer; it was later purchased by Garrards of London.

The Hope Diamond

The Hope Diamond is a large, 45.52 carats (9.10 g), fancy deep blue diamond, currently housed in the Smithsonian Natural History Museum in Washington, D.C. The Hope Diamond is blue to the naked eye because of trace amounts of boron within its crystal structure, but it exhibits red phosphorescence under ultraviolet light. It is classified as a Type IIb diamond, and is famous for supposedly being cursed.

It turned out that he had in his possession an intriguing steel blue stone which at first look seemed to be a large sapphire, but the well-experienced Tavernier soon realized it was a diamond – the largest deep blue diamond in the world

Nassak Diamond

The Nassak Diamond (also known as the Nassac Diamond and the Eye of the Idol) is a large, 43.38 carats (8.68 g) diamond that originated as a larger diamond in the 15th century in India. Found in the Amaragiri mine located in Mahbubnagar, Andhra Pradesh, India, and originally cut in India, the diamond adorned the statue of Shiva in the Trimbakeshwar Shiva Temple, near Nashik, in the state of Maharashtra, India from at least 1500 to 1817. The British East India Company acquired the diamond through the Third Anglo-Maratha War and sold it to British jewelers Rundell and Bridge, in 1818. Rundell and Bridge recut the diamond in 1818, after which it made its way into the handle of the 1st Marquess of Westminster's dress sword.
The Nassak Diamond was imported into the United States in 1927, and was considered one of the first 24 great diamonds of the world by 1930. American jeweler Harry Winston acquired the Nassak Diamond in 1940 in Paris, France and recut it to its present flawless 43.38 carats (8.68 g) emerald cut shape. Winston sold the diamond to a New York jewelry firm in 1942. Mrs. William B. Leeds of New York received the gem in 1944 as a sixth anniversary present and wore it in a ring. The Nassak Diamond was last sold at an auction in New York in 1970 to Edward J. Hand, a 48-year old trucking firm executive from Greenwich, Connecticut.

Excelsior Diamond

The Excelsior Diamond was found on June 30, 1893 at the Jagersfontein Mine by a worker while loading a truck. The man was able to hide the diamond from the supervisors but delivered it to the manager of the mine himself. Until 1905, when the larger Cullinan diamond was found, the Excelsior was the largest known diamond in the world. It had a blue-white tint and weighed 971¾ carats (194.2 g). It was ultimately cut into ten stones weighing from 13 to 68 carats. (2.6 to 13.6 g). Immediately after its discovery the news spread around the world.
The Excelsior I, the largest gem cut from the crystal, was eventually bought by jeweler Robert Mouawad.

Dresden Green Diamond

The Dresden Green diamond is a 41 carats (8.2 g) natural green diamond that has a historical record dating to 1722, when a London news-sheet carried an article about it in its 25 October-27th edition.

In the rough, greenish diamonds tend to occur as one of three types: a stone, often a crystal shape, possessing a light tinge rather like the color of water in a swimming pool; a stone with a dark green skin; a yellowish-green stone characterized by a degree if lubricity. After being cut and polished, diamonds of the first and second types usually lose their greenish color to become white gems or, alternatively, light yellow stones known as "silvery capes". The few truly green faceted diamonds therefore originate from the third type. The famous collection of De Beers Fancy Colored Diamonds, which has been displayed throughtout the world includes some beautiful examples of green diamonds.

Darya-ye Noor Diamond

The Darya-ye Noor "Sea of Light", "River of Light" or "Ocean of Light"; also spelled Darya-i-Noor, Darya-e Noor and Darya-i-Nur is one of the largest diamonds in the world, weighing an estimated 182 carats (36 g). Its colour, pale pink, is one of the rarest to be found in diamonds. The Darya-ye Noor presently forms part of the Iranian Crown Jewels and is on display at the Central Bank of Iran in Tehran.

The Great Table Diamond was one of the many stones shown to the famous jeweler and world traveler Jean-Baptiste Tavernier. In 1642 he documented his observations of this stone, writing that it was one of the “Largest and finest diamonds and rubies seen by him in Europe and Asia”.