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.
Jewellery consists of decorative items worn for personal adornment such as brooches, rings, necklaces, earrings, pendants, bracelets, and cufflinks. Jewellery may be attached to the body or the clothes. From a western perspective, the term is restricted to durable ornaments, excluding flowers for example. For many centuries metal such as gold often combined with gemstones, has been the normal material for jewellery, but other materials such as glass, shells and other plant materials may be used.
Ruby is a pinkish red to blood-red colored gemstone, a variety of the mineral corundum. Ruby is one of the most popular traditional jewelry gems and is very durable. Other varieties of gem-quality corundum are called sapphires. Ruby is one of the traditional cardinal gems, alongside amethyst, sapphire, emerald, and diamond. The word ruby comes from ruber, Latin for red. The color of a ruby is due to the element chromium.
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.
The French Crown Jewels and Regalia comprise the crowns, orb, sceptres, diadems and jewels that were symbols of Royal or Imperial power between 752 and 1870. These were worn by many Kings and Queens of France as well as Emperor Napoleon. The set was finally broken up, with most of it sold off in 1885 by the Third Republic. The surviving French Crown Jewels, principally a set of historic crowns, diadems and parures, are mainly on display in the Galerie d'Apollon of the Louvre, France's premier museum and former royal palace, together with the Regent Diamond, the Sancy Diamond and the 105-carat (21.0 g) Côte-de-Bretagne red spinel, carved into the form of a dragon. In addition, some gemstones and jewels are on display in the Treasury vault of the Mineralogy gallery in the National Museum of Natural History.
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.
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 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 her new surname after marrying John A. Logan following Guggenheim's death. 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.
A gemstone desired to be used in jewelry is cut depending on the size and shape of the rough stone, as well as the desired piece of jewelry to be made. As a general rule, a cut gemstone will reduce the mass by about 50%.
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.
A bezel is a wider and usually thicker section of the hoop of a ring, which may contain a gem or a flat surface. Rings are normally worn to display bezels on the upper or outer side of the finger. In gem-cutting the term bezel is used for those sloping facets of a cut stone that surround the flat table face, which is the large, horizontal facet on the top.
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.
The Maharaja of Indore Necklace is a diamond and emerald-studded necklace. As of 2008, it is on display at the National Museum of Natural History in Washington, D.C., United States. It was originally named the Spanish Inquisition Necklace by the American jeweller Harry Winston, though it had no known connection with the historical Spanish Inquisition. The name was changed in 2021 by the Smithsonian Institution to reflect its actual provenance, having been first owned by Tukoji Rao III, Maharaja of Indore in the early 20th century.
The Napoleon Diamond Necklace is a diamond necklace commissioned by Napoleon I of France c. 1811–1812 from the Parisian jeweler Marie-Étienne Nitot. It is now in the Smithsonian National Museum of Natural History in Washington, D.C.
The Briolette of India is a colorless diamond that was found in India. It is cut in a briolette shape, and is a D-coloured (colourless) type IIa diamond. Its history was thought to date from the 12th century, when it was first acquired by Eleanor of Aquitaine, the Queen consort of King Louis VII of France between 1137 and 1152. This makes the Briolette of India the oldest diamond on record in the world, even older than the famous Koh-i-Noor.
The Bismarck Sapphire Necklace is a sapphire necklace designed by Cartier, Inc. in 1935. As of 2010, the necklace is on display between the Hall Sapphire and Diamond Necklace and the Logan Sapphire in the Janet Annenberg Hooker Hall of Geology, Gems, and Minerals at the Smithsonian Institution's National Museum of Natural History in Washington D.C., United States. It is named after Countess Mona von Bismarck, who donated the piece to the Smithsonian in 1967. The sapphire itself was mined in Burma, and was purchased by the Countess in Sri Lanka in 1926 during her honeymoon with Harrison Williams.
A briolette is a style of gemstone cut. It is an elongated, mostly symmetrical along the main axel, pear shape covered with angular facets usually with a pointed end and no girdle. It is often drilled to hang as a bead. The name is also sometimes erroneously used for pendeloque cut gems. While the briolette is a symmetrical drop shape, the pendeloque cut is flatter and has two different sides: one with a large table facet and one with a point or ridge. The top of a briolette is attached to the piece of jewelry, usually by a hole drilled in the stone, and a pendeloque cut stone needs to be mounted in a prong setting. The briolette is one of the drop cuts for gemstones.
A rivière is a necklace consisting of one or more strings of linked gemstones. Usually only one kind of gemstone is used in a rivière, with all stones of the same colour and cut. The stones are either all the same size, or gradually increase in size towards the middle of the necklace. Rivières have been worn since the 18th century and are still a popular type of necklace.
The Marie Louise Diadem is a diamond and turquoise diadem on permanent display at the National Museum of Natural History in Washington D.C.. It is named for Marie Louise of Austria, the wife of Emperor Napoleon of France.
A pendeloque, from French pendeloque, is a hanging often drop- or pear-shaped object or pendant used as an ornamentation, such as drop-shaped pendant earrings, and specific pear- and drop-shaped parts of chandeliers. The term is also used in describing the specific pendeloque cut for gemstone cutting.
