A gemstone is a piece of mineral crystal which, when cut or polished, is used to make jewelry or other adornments. Certain rocks and occasionally organic materials that are not minerals may also be used for jewelry and are therefore often considered to be gemstones as well. Most gemstones are hard, but some softer minerals such as brazilianite may be used in jewelry because of their color or luster or other physical properties that have aesthetic value. However, generally speaking, soft minerals are not typically used as gemstones by virtue of their brittleness and lack of durability.
The Hope Diamond is a 45.52 carats diamond that has been famed for its great size since the 18th century. Extracted in the 17th century from the Kollur Mine in Guntur, India, the Hope Diamond is a blue diamond. Its exceptional size has revealed new information about the formation of diamonds.
Diamond cutting is the practice of shaping a diamond from a rough stone into a faceted gem. Cutting diamonds requires specialized knowledge, tools, equipment, and techniques because of its extreme difficulty.
The Cullinan Diamond is the largest gem-quality rough diamond ever found, weighing 3,106 carats (621.20 g), discovered at the Premier No.2 mine in Cullinan, South Africa, on 26 January 1905. It was named after Thomas Cullinan, the owner of the mine. In April 1905, it was put on sale in London, but despite considerable interest, it was still unsold after two years. In 1907, the Transvaal Colony government bought the Cullinan and Prime Minister Louis Botha presented it to Edward VII, the British king who reigned over the territory. It was then cut by Joseph Asscher & Co. in Amsterdam.
Tiffany & Co. is an American luxury jewelry and specialty design house headquartered on Fifth Avenue in Manhattan. Tiffany is known for its luxury goods, particularly its sterling silver and diamond jewelry. These goods are sold at Tiffany stores, online, and through corporate merchandising. Its name and branding are licensed to Coty for fragrances and to Luxottica for eyewear.
A diamond cut is a style or design guide used when shaping a diamond for polishing such as the brilliant cut. Cut refers to shape, and also the symmetry, proportioning and polish of a diamond. The cut of a diamond greatly affects a diamond's brilliance—a poorly-cut diamond is less luminous.
A diamond simulant, diamond imitation or imitation diamond is an object or material with gemological characteristics similar to those of a diamond. Simulants are distinct from synthetic diamonds, which are actual diamonds exhibiting the same material properties as natural diamonds. Enhanced diamonds are also excluded from this definition. A diamond simulant may be artificial, natural, or in some cases a combination thereof. While their material properties depart markedly from those of diamond, simulants have certain desired characteristics—such as dispersion and hardness—which lend themselves to imitation. Trained gemologists with appropriate equipment are able to distinguish natural and synthetic diamonds from all diamond simulants, primarily by visual inspection.
The Logan Sapphire is a 422.98-carat (84.596 g) sapphire from Sri Lanka. One of the largest blue faceted sapphires in the world, it was owned by Sir Victor Sassoon and then purchased by M. Robert Guggenheim as a gift for his wife, Rebecca Pollard Guggenheim, who donated the sapphire to the Smithsonian Institution in 1960. The sapphire's name is derived from Rebecca's new surname after marrying John A. Logan. It has been displayed in the National Gem Collection of the National Museum of Natural History in Washington, D.C., since 1971. It is a mixed cushion-cut sapphire, approximately the size of a large chicken egg, and set in a silver and gold brooch surrounded by 20 round brilliant-cut diamonds.
Harry Winston 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.
Prong setting or prong mount refers to the use of metal projections or tines, called "prongs", to secure a gemstone to a piece of jewelry. A prong setting is one component of what is known to jewelers as a head, a claw-shaped type of binding that is welded or soldered to a jewelry item to mount a gemstone to the jewelry item. A common setting for diamond engagement rings, the prong setting allows light to strike a gemstone from more angles, increasing its brilliance.
The largest flawless diamond in the world is known as The Paragon, a D-color gem weighing 137.82 carats (27.564 g), and the tenth largest white diamond in the world. The gem was mined in Brazil and attracted attention for being an exceptional white, flawless stone of great size. The Mayfair-based jeweller Graff Diamonds acquired the stone in Antwerp, cut it into an unusual seven-sided kite shield configuration, and set it in a necklace which separates to both necklace and bracelet lengths. Apart from the main stone, this necklace also contains rare pink, blue, and yellow diamonds, making a total mass of 190.27 carats (38.054 g). The necklace has associations with the end of the millennium and was worn by model Naomi Campbell at a diamond gala held by De Beers and Versace at Syon House in 1999.
Gabriel S. Tolkowsky was a Belgian diamond cutter. He was known for cutting the famous Centenary Diamond, and was one of the world's most renowned diamond cutters. The great nephew of Marcel Tolkowsky, father of the modern round brilliant diamond cut, he is the sixth generation in his family to become well-known in the diamond cutting trade.
Diamond is a gemstone formed by cutting a raw diamond. Diamonds are one of the best-known and most sought-after gems, and they have been used as decorative items since ancient times.
Queen Elizabeth II owned a historic collection of jewels –some as monarch and others as a private individual. They are separate from the gems and jewels of the Royal Collection, and from the coronation and state regalia that make up the Crown Jewels.
The Moon of Baroda is a 24.04 carats (4.808 g) cut diamond discovered in Vadodara (Baroda), India. The diamond, canary yellow in colour, is cut in a pear shape. When found, the rough diamond weighed 25.95 carats (5.190 g). The Moon of Baroda was originally owned by the Maharajas of Baroda. The royal family of Gaekwad Maharajas was in possession of the diamond for almost 500 years. The gem was later worn by singer and actress Marilyn Monroe and Empress Maria Theresa of Austria.
The Patiala Necklace was a necklace designed and made by Cartier in 1928. It was part of the largest ever single order to Cartier to date, made in 1925 by the Indian royal, the Maharaja of Patiala, for the Patiala Necklace and other jewelry worth ₹1,000 million.
The Star of Burma is an 83-carat (16.6 g) cabochon-cut star ruby. In 1935, the Burmese ruby was purchased by Howard Hoeffer of jeweler Trabert & Hoeffer-Mauboussin, whereupon it was used in several Hollywood films in the 1930s, including the musical comedy Vogues of 1938. Trabert & Hoeffer-Mauboussin sold the jewel on September 14, 2004.
Diana, Princess of Wales, owned a collection of jewels both as a member of the British royal family and as a private individual. These were separate from the coronation and state regalia of the crown jewels. Most of her jewels were either presents from foreign royalty, on loan from Queen Elizabeth II, wedding presents, purchased by Diana herself, or heirlooms belonging to the Spencer family.
Larisa Popova is an Italian gemologist, appraiser and jeweler.
The Lion of Merelani is a tsavorite gemstone from Tanzania that is in the collection of the National Museum of Natural History of the Smithsonian Institution in Washington, DC. The gemstone weighs 116.76 carats, has 177 facets, and is an intense green color. It was donated in the memory of Campbell R. Bridges, the gemologist who discovered tsavorite, who was murdered in 2009. It is the largest known tsavorite gemstone and the largest fine gemstone ever to be cut and polished in the United States.
