|
Star Of Sierra Leone
The Star of Sierra Leone diamond was discovered by miners on February 14, 1972, in the Diminco alluvial mines in the Koidu area of Sierra Leone. It ranks as the fourth-largest gem-quality diamond and the largest alluvial diamond ever discovered. On October 3, 1972, Sierra Leone's then-President, Siaka Stevens, announced that Harry Winston, the New York City jeweller, had purchased the Star of Sierra Leone for under $2.5 million. The stone was initially cut into an emerald shaped stone weighing but was later re-cut due to an internal flaw, eventually resulting in 17 separate finished diamonds, of which 13 were deemed to be flawless. The largest single finished gem was a flawless pear-shaped diamond of . Six of the diamonds cut from the original rough were later set by Harry Winston into the "Star of Sierra Leone" brooch. A rare characteristic of the stone is its perfect chemical purity: it is ranked as a type IIa diamond, a category which includes less than 1% of all diamonds.< ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sierra Leone
Sierra Leone,)]. officially the Republic of Sierra Leone, is a country on the southwest coast of West Africa. It is bordered by Liberia to the southeast and Guinea surrounds the northern half of the nation. Covering a total area of , Sierra Leone has a tropical climate, with diverse environments ranging from savanna to rainforests. The country has a population of 7,092,113 as of the 2015 census. The capital and largest city is Freetown. The country is divided into five administrative regions, which are subdivided into Districts of Sierra Leone, 16 districts. Sierra Leone is a constitutional republic with a unicameral parliament and a directly elected executive president, president serving a five-year term with a maximum of two terms. The current president is Julius Maada Bio. Sierra Leone is a Secular state, secular nation with Constitution of Sierra Leone, the constitution providing for the separation of state and religion and freedom of conscience (which includes freedom of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Harry Winston
Harry Winston (March 1, 1896December 8, 1978) was an American jeweler. He donated the Hope Diamond to the Smithsonian Institution in 1958 after owning it for a decade. He also traded the Portuguese Diamond to the Smithsonian in 1963 in exchange for 3,800 carats of small diamonds. Winston founded the Harry Winston Inc. in New York City in 1932. He had been called by many the "King of Diamonds". History Winston's father Jacob started a small jewelry business. He and Winston's mother were Jewish immigrants to the United States from the Russian Empire. While growing up, Harry worked in his father's shop. When he was twelve years old, he recognized a two-carat emerald in a pawn shop, bought it for 25 cents, and sold it two days later for $800. Winston started his business in 1920 and opened his first store in New York City in 1932. Winston's jewelry empire began in 1926, with his acquisition of Arabella Huntington's jewelry collection, for $1.2 million. The wife of railroad mag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diamond
Diamond is a Allotropes of carbon, solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic. Another solid form of carbon known as graphite is the Chemical stability, chemically stable form of carbon at Standard conditions for temperature and pressure, room temperature and pressure, but diamond is metastable and converts to it at a negligible rate under those conditions. Diamond has the highest Scratch hardness, hardness and thermal conductivity of any natural material, properties that are used in major industrial applications such as cutting and polishing tools. They are also the reason that diamond anvil cells can subject materials to pressures found deep in the Earth. Because the arrangement of atoms in diamond is extremely rigid, few types of impurity can contaminate it (two exceptions are boron and nitrogen). Small numbers of lattice defect, defects or impurities (about one per million of lattice atoms) color diamond blue (bor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mining In Sierra Leone
The mining industry of Sierra Leone accounted for 4.5 percent of the country's GDP in 2007 and minerals made up 79 percent of total export revenue with diamonds accounting for 46 percent of export revenue in 2008. The main minerals mined in Sierra Leone are diamonds, rutile, bauxite, gold, iron and limonite. Mining in Sierra Leone has been seen as one of the key factors for instability in the country and one of the reasons for the country's recent civil war. Traditionally, benefits from diamond mining have ended up with private companies and corrupt officials rather than the country's government and people. The Ministry of Mineral Resources is responsible for the management of the country's minerals sector and the Mines and Minerals Act 2009. Sierra Leone is a candidate for the Extraction Industries Transparency Initiative (EITI). GoSL publishes data on licenses and payments by mining companies on their Online Repository established by Revenue Development Foundation, the rep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Koidu
Koidu Town (or Sefadu) is the capital and largest city of the diamond-rich Kono District in the Eastern Province of Sierra Leone. The population of Koidu Town is 124,6based on the 2015 Sierra Leone national census. Koidu Town is the fifth largest city in Sierra Leone by population, after Freetown, Kenema, Bo and Makeni. Koidu Town is a major urban, business, commercial and diamond trade center. Koidu Town lies approximately 280 miles east of Freetown, and about 60 miles north of Kenema. Two of the world’s ten largest and most famous rough diamonds were found in the Woyie River that flows through Koidu Town. The city is officially known as Koidu City. The mayor of Koidu City and members of the Koidu-New Sembehun city council are directly elected every four years by the residents of Koidu. The current mayor of Koidu Town is Komba Sam of the Coalition 4 Change [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Siaka Stevens
Siaka Probyn Stevens (24 August 1905 – 29 May 1988) was the leader of Sierra Leone from 1967 to 1985, serving as Prime Minister of Sierra Leone, Prime Minister from 1967 to 1971 and as President from 1971 to 1985. Stevens' leadership was often characterized by patrimonial rule and self-indulgence, consolidating power by means of corruption and exploitation. Stevens and his All People's Congress (APC) party won the closely contested 1967 Sierra Leone general elections over incumbent Prime Minister Sir Albert Margai of the Sierra Leone People's Party (SLPP). In April 1971, Stevens made Sierra Leone a republic and became president a day after the constitution had been ratified by the Sierra Leone Parliament. Though generally considered as the first president of Sierra Leone, technically he was the second President of the Republic after Christopher Okoro Cole, a judge, who was sworn in for a day after which he resigned, paving the way for Stevens. Stevens served as Chairman of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diamond Type
Diamond type is a method of scientifically classifying diamonds by the level and type of their chemical impurities. Diamonds are separated into five types: Type Ia, Type Ib, Type 1aB, Type IIa, and Type IIb. The impurities measured are at the atomic level within the crystal lattice of carbon atoms and so, unlike inclusions, require an infrared spectrometer to detect. Different diamond types react in different ways to diamond enhancement techniques. Different types can coexist within a single stone; natural diamonds are often mixes of Type Ia and Ib, which can be determined by their infrared absorption spectrum. Types of Diamond Type I Type I diamonds, the most common class, contain nitrogen atoms as their main impurity, commonly at a concentration of 0.1%. Type I diamonds absorb in both the infrared and ultraviolet region, from 320 nm. They also have a characteristic fluorescence and visible absorption spectrum (see Optical properties o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Diamonds
Diamond (gemstone), Diamonds become famous typically for some combination of their size, color and quality. Diamonds occur naturally in many different colors, so the largest diamond of a particular color may not be large in absolute terms, but it may still be considered very desirable. Diamonds may also have high valuations or sale prices, or go on to have a noteworthy ownership history, but this will tend to occur for diamonds that had some outstanding characteristic to begin with. As new diamonds are discovered, the uniqueness of existing ones may diminish and there is no agreed-upon measure of a large or a high-quality diamond, so a strict inclusion criteria for notable diamonds is not attainable. Diamond A diamond is a Allotropes of carbon, solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic. At Standard conditions for temperature and pressure, room temperature and pressure, another solid form of carbon known as graphite is the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diamonds Originating In Sierra Leone
Diamond is a Allotropes of carbon, solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic. Another solid form of carbon known as graphite is the Chemical stability, chemically stable form of carbon at Standard conditions for temperature and pressure, room temperature and pressure, but diamond is metastable and converts to it at a negligible rate under those conditions. Diamond has the highest Scratch hardness, hardness and thermal conductivity of any natural material, properties that are used in major industrial applications such as cutting and polishing tools. They are also the reason that diamond anvil cells can subject materials to pressures found deep in the Earth. Because the arrangement of atoms in diamond is extremely rigid, few types of impurity can contaminate it (two exceptions are boron and nitrogen). Small numbers of lattice defect, defects or impurities (about one per million of lattice atoms) color diamond blue (bor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
