Majorica is a Spanish company that manufactures hand-made pearls called Majorica pearls. [1] Now based in Majorca, the company was founded in 1890 in Barcelona. [1] In 1990, Gems & Gemology described Majorica pearls as "the most widely marketed and meticulously manufactured imitation [pearl] today". [1]
Majorica imitation pearls are man-made on solid balls, likely made of glass, that are coated with a proprietary coating that is made in part from fish scales. [1] The coated nuclei are then dried and polished, and then dipped in a chemical (possibly cellulose acetate and cellulose nitrate) to harden the surface and guard against discoloration, chipping, and peeling. [1]
Amethyst is a violet variety of quartz. The name comes from the Koine Greek αμέθυστος amethystos from α- a-, "not" and μεθύσκω methysko / μεθώ metho, "intoxicate", a reference to the belief that the stone protected its owner from drunkenness. Ancient Greeks wore amethyst and carved drinking vessels from it in the belief that it would prevent intoxication.
Emerald is a gemstone and a variety of the mineral beryl (Be3Al2(SiO3)6) colored green by trace amounts of chromium or sometimes vanadium. Beryl has a hardness of 7.5–8 on the Mohs scale. Most emeralds have lots of material trapped inside during the gem's formation, so their toughness (resistance to breakage) is classified as generally poor. Emerald is a cyclosilicate.
A gemstone is a piece of mineral crystal which, in cut and polished form, is used to make jewelry or other adornments. However, certain rocks and occasionally organic materials that are not minerals are also used for jewelry and are therefore often considered to be gemstones as well. Most gemstones are hard, but some soft minerals are used in jewelry because of their luster or other physical properties that have aesthetic value. Rarity and notoriety are other characteristics that lend value to gemstones.
A pearl is a hard, glistening object produced within the soft tissue of a living shelled mollusk or another animal, such as fossil conulariids. Just like the shell of a mollusk, a pearl is composed of calcium carbonate in minute crystalline form, which has deposited in concentric layers. The ideal pearl is perfectly round and smooth, but many other shapes, known as baroque pearls, can occur. The finest quality of natural pearls have been highly valued as gemstones and objects of beauty for many centuries. Because of this, pearl has become a metaphor for something rare, fine, admirable and valuable.
Gemology or gemmology is the science dealing with natural and artificial gemstone materials. It is a geoscience and a branch of mineralogy. Some jewelers are academically trained gemologists and are qualified to identify and evaluate gems.
Celluloids are a class of materials produced by mixing nitrocellulose and camphor, often with added dyes and other agents. Once much more common for its use as photographic film before the advent of safer methods, celluloid's common contemporary uses are for manufacturing table tennis balls, musical instruments, combs, office equipment, fountain pen bodies, and guitar picks.
Fiber or fibre is a natural or artificial substance that is significantly longer than it is wide. Fibers are often used in the manufacture of other materials. The strongest engineering materials often incorporate fibers, for example carbon fiber and ultra-high-molecular-weight polyethylene.
Cellophane is a thin, transparent sheet made of regenerated cellulose. Its low permeability to air, oils, greases, bacteria, and liquid water makes it useful for food packaging. Cellophane is highly permeable to water vapour, but may be coated with nitrocellulose lacquer to prevent this.
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, and it was cut by Joseph Asscher & Co. in Amsterdam.
In gemology, aventurescence is an optical reflectance effect seen in certain gems. The effect amounts to a metallic glitter, arising from minute, preferentially oriented mineral platelets within the material. These platelets are so numerous that they also influence the material's body colour. In aventurine quartz chrome-bearing fuchsite produces a green stone, and various iron oxides produce a red stone.
Demantoid is the green gemstone variety of the mineral andradite, a member of the garnet group of Minerals. Andradite is a calcium- and iron-rich garnet. The chemical formula is Ca3Fe2(SiO4)3 with chromium substitution as the cause of the demantoid green color. Ferric iron is the cause of the yellow in the stone.
The Gemological Institute of America (GIA) is a nonprofit institute based in Carlsbad, California. It is dedicated to research and education in the field of gemology and the jewelry arts. Founded in 1931, GIA's mission is to protect buyers and sellers of gemstones by setting and maintaining the standards used to evaluate gemstone quality. The institute does so through research, gem identification and diamond grading services and a variety of educational programs. Through its library and subject experts, GIA acts as a resource of gem and jewelry information for the trade, the public and media outlets.
Gems & Gemology is a quarterly scientific journal published by the Gemological Institute of America. Each issue is devoted to research on diamonds, gemstones, and pearls. Topics include geographic sources, imitations and synthetics, treatments, and identification techniques. Established in January 1934, Gems & Gemology is geared toward jewelry professionals and gemologists.
Ammolite is an opal-like organic gemstone found primarily along the eastern slopes of the Rocky Mountains of North America. It is made of the fossilized shells of ammonites, which in turn are composed primarily of aragonite, the same mineral contained in nacre, with a microstructure inherited from the shell. It is one of few biogenic gemstones; others include amber and pearl.1 In 1981, ammolite was given official gemstone status by the World Jewellery Confederation (CIBJO), the same year commercial mining of ammolite began. It was designated the official gemstone of the City of Lethbridge, Alberta in 2007.
Gemstone irradiation is a process in which a gemstone is artificially irradiated in order to enhance its optical properties. High levels of ionizing radiation can change the atomic structure of the gemstone's crystal lattice, which in turn alters the optical properties within it. As a result, the gemstone's color may be significantly altered or the visibility of its inclusions may be lessened.
Melo melo, common name the Indian volute or bailer shell, is a very large edible sea snail, a marine gastropod mollusc in the family Volutidae, the volutes.
Richard T. Liddicoat, Jr. was an American gemologist. Liddicoat was an educator in gemology, who also made contributions in the area of diamond quality grading and gem identification. Liddicoat was the Chairman of the Board of Governors at the Gemological Institute of America (GIA).
PB Swiss Tools AG is a manufacturer of hand tools based in Switzerland.
The Abernethy pearl, also known as the Little Willie pearl, is a 43.60-grain (2.825 g) freshwater pearl discovered in the River Tay, Scotland in 1967. The pearl is named after its discoverer, William Abernethy (1925–2021). It was previously known as Bill's pearl.
Aquamarine is a pale-blue to light-green variety of beryl. The color of aquamarine can be changed by heat.
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