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This is a list of gemstones, organized by species and types.
| | This article needs additional citations for verification .(January 2019) |
This is a list of gemstones, organized by species and types.
There are over 300 types of minerals that have been used as gemstones. Such as:
There are a number of artificial and lab grown minerals used to produce gemstones. These include:
There are a number of organic materials used as gems, including:
Some rocks are used as gems, including:
Some minerals made into gemstones may display a chatoyancy or cat's eye effect, these include: [1]
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.
In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid substance with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.
A pegmatite is an igneous rock showing a very coarse texture, with large interlocking crystals usually greater in size than 1 cm (0.4 in) and sometimes greater than 1 meter (3 ft). Most pegmatites are composed of quartz, feldspar, and mica, having a similar silicic composition to granite. However, rarer intermediate composition and mafic pegmatites are known.
The mineral or gemstone chrysoberyl is an aluminate of beryllium with the formula BeAl2O4. The name chrysoberyl is derived from the Greek words χρυσός chrysos and βήρυλλος beryllos, meaning "a gold-white spar". Despite the similarity of their names, chrysoberyl and beryl are two completely different gemstones, although they both contain beryllium. Chrysoberyl is the third-hardest frequently encountered natural gemstone and lies at 8.5 on the Mohs scale of mineral hardness, between corundum (9) and topaz (8).
Lustre or luster is the way light interacts with the surface of a crystal, rock, or mineral. The word traces its origins back to the Latin lux, meaning "light", and generally implies radiance, gloss, or brilliance.
Pleochroism is an optical phenomenon in which a substance has different colors when observed at different angles, especially with polarized light.
Chemistry is the physical science concerned with the composition, structure, and properties of matter, as well as the changes it undergoes during chemical reactions.
Silicate minerals are rock-forming minerals made up of silicate groups. They are the largest and most important class of minerals and make up approximately 90 percent of Earth's crust.
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.
Andradite is a mineral species of the garnet group. It is a nesosilicate, with formula Ca3Fe2Si3O12.
A metamorphic facies is a set of mineral assemblages in metamorphic rocks formed under similar pressures and temperatures. The assemblage is typical of what is formed in conditions corresponding to an area on the two dimensional graph of temperature vs. pressure. Rocks which contain certain minerals can therefore be linked to certain tectonic settings, times and places in the geological history of the area. The boundaries between facies are wide because they are gradational and approximate. The area on the graph corresponding to rock formation at the lowest values of temperature and pressure is the range of formation of sedimentary rocks, as opposed to metamorphic rocks, in a process called diagenesis.
Ammolite is an opal-like organic gemstone found primarily along the eastern slopes of the Rocky Mountains of North America. It is commonly unearthed by natural erosion or through the process of various mining practices, within the perimeter of an ancient sea bed called the Western Interior Seaway. 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.
A range of gemstones are mentioned in the Bible, particularly in the Old Testament and the Book of Revelation. Much has been written about the precise identification of these stones, which has ranged from speculative to increasingly scientific with the advent of archeogemology.
Mining is an important industry in Pakistan. Pakistan has deposits of several minerals including coal, copper, gold, chromite, mineral salt, bauxite and several other minerals. There are also a variety of precious and semi-precious minerals that are also mined. These include peridot, aquamarine, topaz, ruby, emerald, rare-earth minerals bastnaesite and xenotime, sphene, tourmaline, and many varieties and types of quartz.
There are many types of gemstones of Pakistan. They can be found among the nation's three mountain ranges - the Hindu Kush, the Himalayas, and the Karakoram - in the provinces of Khyber Pakhtunkhwa, Gilgit-Baltistan, Balochistan, and the Federally Administered Tribal Areas. The gemstone industry in Pakistan has the city of Peshawar as its hub, and there are many companies working in it.
A subduction zone is a region of the Earth's crust where one tectonic plate moves under another tectonic plate; oceanic crust gets recycled back into the mantle and continental crust gets produced by the formation of arc magmas. Arc magmas account for more than 20% of terrestrially produced magmas and are produced by the dehydration of minerals within the subducting slab as it descends into the mantle and are accreted onto the base of the overriding continental plate. Subduction zones host a unique variety of rock types formed by the high-pressure, low-temperature conditions a subducting slab encounters during its descent. The metamorphic conditions the slab passes through in this process generates and alters water bearing (hydrous) mineral phases, releasing water into the mantle. This water lowers the melting point of mantle rock, initiating melting. Understanding the timing and conditions in which these dehydration reactions occur, is key to interpreting mantle melting, volcanic arc magmatism, and the formation of continental crust.
The Cross of Adelheid is an 11th-12th century reliquary in the form of a crux gemmata. It is held in Saint Paul's Abbey, Lavanttal. It was commissioned by Adelheid, daughter of Rudolf of Rheinfelden, passing to St. Blaise Abbey in the 19th century before coming to its present home. The Cross of Adelheid is known as the largest German reliquary to survive from the High Middle Ages. It is made of a wooden core covered with gilded silver plate. The four arms of the cross extend from the middle square. The lower arm is the longest and the other three are the same length. Each arm of the Cross ends in a square. On the front are gems, pearls and precious stones. It is 82.9 cm high, 65.4 cm wide and 7.4 to 7.8 cm deep. There are a total of 170 gems on the cross, with only 147 remaining. The remaining gems are: 47 amethysts, 22 carnelians, 17 agates, 13 rock crystals, 7 moonstones, 6 garnets, 5 chalcedonies, 5 onyxes, 4 almandines, 4 heliotropes, 3 turquoises, 2 beryls, 2 serpentines, 1 lapis lazuli, 1 emerald, 1 milk opal and 1 smoky quartz.
The Allison and Roberto Mignone Halls of Gems and Minerals are a series of exhibition halls at the American Museum of Natural History on the Upper West Side in Manhattan, New York City. The halls opened on June 12, 2021, as a complete redesign of their predecessors, the Harry Frank Guggenheim Hall of Gems and Minerals and Morgan Memorial Hall of Gems. The halls feature thousands of rare gems, mineral specimens and pieces of jewelry.
Colophonite, less commonly kalophonit (from Ancient Greek: κολοφωνία, kolophonia, rosin or rosin colors) — an obsolete historical name for a brownish calcium-iron mineral of the garnet family, a variety of grossular (later, andradite), discovered as an associated metamorphic mineral in the iron ore mines of the southern Norwegian islands, primarily Tromø (near Arendal). It is a nesosilicate, with formula Ca3Fe3+2(SiO4)3. Other names for colophonite: resin garnet (French: Grenat résinite), calderite, rosin garnet.
Gemmological classifications by E. Ya. Kievlenko (1980), updated | |||||||||
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