Gemstones

Datolite is a calcium boron hydroxide nesosilicate, CaBSiO4(OH). It was first observed by Jens Esmark in 1806, and named by him from δατεῖσθαι, "to divide," and λίθος, "stone," in allusion to the granular structure of the massive mineral.

Xenotime is a rare-earth phosphate mineral, the major component of which is yttrium orthophosphate (YPO4). The phosphate ions are described by a tetrahedral shape and coordinate to the center Y3+ metal ion in a way that closely resembles the structure of zircon (ZrSiO4). It forms a solid solution series with chernovite-(Y) (YAsO4) and therefore may contain trace impurities of arsenic, as well as silicon dioxide and calcium. Other iso-structural ions that undergo exchanges with PO4 are VO4 and NbO4 ions, contributing to the list of possible co-occurring elements that may be in need of separatio

Danburite is a calcium boron silicate mineral with a chemical formula of CaB2(SiO4)2.

Humite is a mineral found in the volcanically ejected masses of Vesuvius. It was first described in 1813 and named for Abraham Hume (1749–1838).

Afghanite, (Na,K)22Ca10[Si24Al24O96](SO4)6Cl6, is a hydrous sodium, calcium, potassium, sulfate, chloride, carbonate alumino-silicate mineral. Afghanite is a feldspathoid of the cancrinite group and typically occurs with sodalite group minerals. It forms blue to colorless, typically massive crystals in the trigonal crystal system. The lowering of the symmetry from typical (for cancrinite group) hexagonal one is due to ordering of Si and Al. It has a Mohs hardness of 5.5 to 6 and a specific gravity of 2.55 to 2.65. It has refractive index values of nω = 1.523 and nε = 1.529. It has one directio

Wavellite is an aluminium basic phosphate mineral with formula Al3(PO4)2(OH, F)3·5H2O. Distinct crystals are rare, and it normally occurs as translucent green radial or spherical clusters.

Painite is a rare borate mineral. It was first found in Myanmar by British mineralogist and gem dealer Arthur C.D. Pain who misidentified it as ruby, until it was discovered as a new gemstone in the 1950s. When it was confirmed as a new mineral species, the mineral was named after him.

Elbaite, a sodium, lithium, aluminium boro-silicate, with the chemical composition Na(Li1.5Al1.5)Al6Si6O18(BO3)3(OH)4, is a mineral species belonging to the six-member ring cyclosilicate tourmaline group.

Moldavite () is a forest green, olive green or blue greenish vitreous silica projectile glass formed by a meteorite impact in southern Germany (Nördlinger Ries Crater) that occurred about 15 million years ago. It is a type of tektite and a gemstone. Material ejected from the impact crater includes moldavite, which was strewn across parts of Germany, the Czech Republic and Austria.

Pectolite is a white to gray mineral, NaCa2Si3O8(OH), a sodium calcium hydroxide inosilicate. It crystallizes in the triclinic system typically occurring in radiated or fibrous crystalline masses. It has a Mohs hardness of 4.5 to 5 and a specific gravity of 2.7 to 2.9. A highly sought-after variety known as larimar, is a pale to sky blue. There is also a whitish form of the mineral from Alaska that is sometimes marketed as 'Alaska jade'.

thumb|Spectacle bracelet in dumortierite and gold by Cora Sheibani Dumortierite is a fibrous variably colored aluminium boro-silicate mineral, Al7BO3(SiO4)3O3. It crystallizes in the orthorhombic system typically forming fibrous aggregates of slender prismatic crystals. The crystals are vitreous and vary in color from brown, blue, and green to more rare violet and pink. Substitution of iron and other tri-valent elements for aluminium results in the color variations. It has a Mohs hardness of 7 and a specific gravity of 3.3 to 3.4. Crystals show pleochroism from red to blue to violet. Dumortier

Sunstone is a microcline or oligoclase feldspar, which when viewed from certain directions exhibits a spangled appearance. It has been found in Southern Norway, Sweden, various localities in the United States, and on some beaches along the midcoast of South Australia.

Brazilianite, whose name derives from its country of origin, Brazil, is a typically yellow-green phosphate mineral, most commonly found in phosphate-rich pegmatites.

beryl variety

Tugtupite is a beryllium aluminium tectosilicate. It also contains sodium and chlorine and has the formula Na4AlBeSi4O12Cl. Tugtupite is a member of the silica-deficient feldspathoid mineral group. It occurs in high alkali intrusive igneous rocks.

thumb|Red zircon from Gilgit, [[Pakistan]]

Taaffeite (; BeMgAl4O8) is a mineral, named after its discoverer Richard Taaffe (1898–1967) who found the first sample, a cut and polished gem, in October 1945 in a jeweler's shop in Dublin, Ireland. As such, it is the only gemstone to have been initially identified from a faceted stone. Taaffeite is a million times rarer than diamonds and comes in shades of purple, pink, red. Most pieces of the gem, prior to Taaffe, had been misidentified as spinel. For many years afterwards, it was known only in a few samples, and it is still one of the rarest gemstone minerals in the world.

Sugilite ( ) is a relatively rare pink to purple cyclosilicate mineral with the complex chemical formula KNa2(Fe, Mn, Al)2Li3Si12O30. Sugilite crystallizes in the hexagonal system with prismatic crystals. The crystals are rarely found and the form is usually massive. It has a Mohs hardness of 5.5–6.5 and a specific gravity of 2.75–2.80. It is mostly translucent. Sugilite was first described in 1944 by the Japanese petrologist Ken-ichi Sugi (1901–1948) for an occurrence on Iwagi Islet, Japan, where it is found in an aegirine syenite intrusive stock. It is found in a similar environment at

chemical compound

Variscite is a hydrated aluminium phosphate mineral (). It is a relatively rare phosphate mineral. It is sometimes confused with turquoise; however, variscite is usually greener in color. The green color results from the presence of small amounts of trivalent chromium ().

beryl var.

Pezzottaite, marketed under the name raspberyl or raspberry beryl, is a mineral species first recognized by the International Mineralogical Association in September 2003. Pezzottaite is a caesium analogue of beryl, a silicate of caesium, beryllium, lithium and aluminium, with the chemical formula Cs(Be2Li)Al2Si6O18. Named after Italian geologist and mineralogist Federico Pezzotta, pezzottaite was first thought to be either red beryl or a new variety of beryl ("caesium beryl"); unlike actual beryl, however, pezzottaite contains lithium and crystallizes in the trigonal crystal system rather than

Ekanite is an uncommon silicate mineral with chemical formula or . It is a member of the steacyite group. It is among the few gemstones that are naturally radioactive. Most ekanite is mined in Sri Lanka, although deposits also occur in Russia and North America. Clear and well-colored stones are rare as the radioactivity tends to degrade the crystal matrix over time in a process known as metamictization.

Sapphirine is a rare mineral, a silicate of magnesium and aluminium, with the chemical formula ( (with iron as a major impurity). Named for its sapphire-like colour, sapphirine is primarily of interest to researchers and collectors: well-formed crystals are treasured and occasionally cut into gemstones. Sapphirine has also been synthesized for experimental purposes via a hydrothermal process.

Bayldonite (BAIL-done-ite) is a rare secondary mineral with the chemical formula PbCu3(AsO4)2(OH)2. Its provenance has been attributed to Penberthy Croft Mine, Cornwall, England, United Kingdom but there is no substantiating evidence for this and it was only attributed to Cornwall by Church (1865). Also, Church’s paper (Church, 1865) clearly states “I am indebted to Mr. Talling for this mineral species also.” so the original material was supplied by the mineral dealer Richard Talling and not discovered by Bayldon. Bayldonite was named after Church's dear friend and colleague at the Royal Agric

thumb|260px|Specimen from Santiago de Compostela, Spain

Serandite is a mineral with formula Na(Mn2+,Ca)2Si3O8(OH). The mineral was discovered in Guinea in 1931 and named for J. M. Sérand. Serandite is generally red, brown, black or colorless. The correct name lacks an accent.

thumb|upright=0.6|Pounamu barb thumb|upright|Pounamu pendant, a heavily stylized fishhook thumb|The southwest coast of New Zealand is named ("The greenstone waters"), after its deposits of greenstone, and the area resembles greenstone in this view from space. The term is also the official Māori language|Māori name for the [[South Island.]]

type of green serpentinite breccia rock with a high calcite content

Clinohumite is an uncommon member of the humite group, a magnesium silicate according to the chemical formula (Mg, Fe)9(SiO4)4(F,OH)2. The formula can be thought of as four olivine (Mg2SiO4), plus one brucite (Mg(OH)2). Indeed, the mineral is essentially a hydrated olivine and occurs in altered ultramafic rocks and carbonatites. Most commonly found as tiny indistinct grains, large euhedral clinohumite crystals are sought by collectors and occasionally fashioned into bright, yellow-orange gemstones. Only two sources of gem-quality material are known: the Pamir Mountains of Tajikistan, and the T

Kornerupine (also called Prismatine) is a rare boro-silicate mineral with the chemical formula . It crystallizes in the orthorhombic – dipyramidal crystal system as brown, green, yellow to colorless slender tourmaline like prisms or in massive fibrous forms. It has a Mohs hardness of 7 and a specific gravity of 3.3 to 3.34. Its indices of refraction are nα=1.660 – 1.671, nβ=1.673 – 1.683 and nγ=1.674 – 1.684.

Lithiophilite is a mineral containing the element lithium. It is lithium manganese(II) phosphate with chemical formula . It occurs in pegmatites often associated with triphylite, the iron end member in a solid solution series. The mineral with intermediate composition is known as sicklerite and has the chemical formula ). The name lithiophilite is derived from the Greek philos () "friend", as lithiophilite is usually found with lithium.

Hyalophane or jaloallofane is a crystalline mineral, part of the feldspar group of tectosilicates. It is considered a barium-rich potassium feldspar. Its chemical formula is , and it has a hardness of 6 to . The name hyalophane comes from the Greek , meaning "glass", and meaning "to appear".

Grandidierite is a rare mineral that was first discovered in 1902 in southern Madagascar. The mineral was named in honor of French explorer Alfred Grandidier (1836–1912) who studied the natural history of Madagascar. thumb|left|A large, faceted grandidierite, a 429.87 carat stone owned by a Filipino collector Benedicto G. Membrere V. GIL Report certificate number STN201811139168.

Shattuckite is a copper silicate hydroxide mineral with formula Cu5(SiO3)4(OH)2. It crystallizes in the orthorhombic – dipyramidal crystal system and usually occurs in a granular massive form and also as fibrous acicular crystals. It is closely allied to plancheite in structure and appearance.

glittering glass made in a low-oxygen reducing atmosphere

Papagoite is a rare cyclosilicate mineral. Chemically, it is a calcium copper aluminium silicate hydroxide, found as a secondary mineral on slip surfaces and in altered granodiorite veins, either in massive form or as microscopic crystals that may form spherical aggregates. Its chemical formula is Ca Cu Al Si2O6(O H)3.

Thulite (sometimes called rosaline) is a translucent, crystalline or massive pink manganese-bearing variety of the mineral zoisite. Manganese substitutes for calcium in the structure with up to two percent Mn2+. Thulite is often mottled with white calcite and occurs as veins and fracture fillings transecting many types of rock. In mineralogical literature, thulite may sometimes refer to any pink zoisite. Clinothulite is the manganese bearing variety of monoclinic clinozoisite.

Fluorapatite, often with the alternate spelling of fluoroapatite, is a phosphate mineral with the formula Ca5(PO4)3F (calcium fluorophosphate). Fluorapatite is a hard crystalline solid. Although samples can have various colors (green, brown, blue, yellow, violet, or colorless), the pure mineral is colorless, as expected for a material lacking transition metals. Along with hydroxylapatite, it can be a component of tooth enamel, especially in individuals who use fluoridated toothpaste, but for industrial use both minerals are mined in the form of phosphate rock, whose usual mineral composition i

Larimar is the tradename for a rare blue variety of the silicate mineral pectolite found only in Dominican Republic, around the city of Barahona. Its coloration varies from bluish white, light-blue, light-green, green-blue, turquoise blue, turquoise green, turquoise blue-green, deep green, dark green, to deep blue, dark blue and purple, violet and indigo and the larimar can come in many varieties and color mixes.

variety of beryl

Eosphorite is a brown (occasionally pink) manganese hydrous phosphate mineral with chemical formula: MnAl(PO4)(OH)2·H2O. It is used as a gemstone.

Poudretteite is an extremely rare mineral and gemstone that was first discovered as minute crystals in Mont St. Hilaire, Quebec, Canada, during the 1960s. The mineral was named for the Poudrette family because they operated a quarry in the Mont St. Hilaire area where poudretteite was originally found, and the quarry is currently owned by the United Kingdom based Salmon Mining Industries Inc. Poudretteite has a barely detectable radioactivity.

Stichtite is a mineral, a carbonate of chromium and magnesium; formula Mg6Cr2CO3(OH)16·4H2O. Its colour ranges from pink through lilac to a rich purple colour. It is formed as an alteration product of chromite-containing serpentine. It occurs in association with barbertonite (the hexagonal polymorph of Mg6Cr2CO3(OH)16·4H2O), chromite and antigorite.

Rubellite is the red or pink variety of tourmaline and is a member of the elbaite. It is also the rarest gem in its family. It is occasionally mistaken for ruby. These gems typically contain inclusions.

Unakite is a coarse-grained metamorphic rock that is an altered granitoid composed of orthoclase feldspar (pink), epidote (yellow-green), and quartz (smokey or colorless). Albite-oligoclase plagioclase (white) may or may not be also present.

Musgravite or magnesiotaaffeite-6N’3S is a rare oxide mineral used as a gemstone. Its type locality is the Ernabella Mission, Musgrave Ranges, South Australia, for which it was named following its discovery in 1967. It is a member of the taaffeite family of minerals, and its chemical formula is Be(Mg, Fe, Zn)2Al6O12. Its hardness is 8 to 8.5 on the Mohs scale. Due to its rarity, the mineral can sell for roughly USD$35,000 per carat.

Tinaksite (chemical formula ) is a mineral found in northern Russia. Tinaksite can be grayish-white, yellowish, orange, or brown, and it is often found in charoite. Its name is derived from its composition: titanium (Ti), sodium (Na) potassium (K) and silicon (Si). The International Mineralogical Association first recognized tinaksite as a mineral in 1965.

Stibiotantalite is a tantalate mineral found in complex granite pegmatites. Stibiotantalite constitutes the tantalum endpoint of a solid solution series with its niobium analogue stibiocolumbite.

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Rumanite is a rare variety of fossilized tree resin (amber), known for its deep reddish to brownish hues. It is found exclusively in Romania, particularly in the sandstone deposits of the Buzău River system near the village of Colți in Buzău County.

small stones rubbed for anxiety

thumb|Anyolite from Mundarara Mine, Tanzania. Red colored ruby inclusions are visible. Anyolite is a metamorphic rock composed of intergrown green zoisite, black/dark green pargasite and ruby. It has been found in the Arusha Region of Tanzania and in Austria. It is sometimes incorrectly advertised as a variety of the mineral zoisite. The term anyolite is, however, not an officially accepted term for a metamorphic rock. Its name derives from the Maasai word anyoli, meaning "green". Anyolite is also referred to as ruby in zoisite, ruby zoisite, ruby-zoisite or Tanganyika artstone.

thumb|270px|Hiddenite thumb|270px|Hiddenite Hiddenite is a pale-to-emerald green variety of spodumene that is sometimes used as a gemstone.

thumb|Zircon (Field of view|FOV from [[Mont Saint-Hilaire, Canada]] Jargoon or jargon (occasionally in old writings jargounce and jacounce) is a name applied by gemologists to zircons that are of sufficient quality to be cut as gemstones, but not the red color that characterizes the hyacinth or jacinth. The word is related to Persian (zircon; zar-gun, "gold-like" or "as gold").

crystal that has been artificially coated with gold fumes

thumb|380x380px|An example of a variscite "callaïs" necklace of Neolithic origin, dated 4500 - 4000 BC, found in Arzon. The necklace now located in the Musée d'Histoire et d'Archéologie de Vannes. Callaïs is the generic name for ancient green-blue precious stones used for making pendants and beads by western European cultures of the later Neolithic and early Bronze Age. The term includes turquoise and variscite but not jade. "Callaïs" was described by Pliny the Elder as being paler than lapis lazuli. Callaïs objects have been found in Neolithic tombs from the mid-5th millennium BC in the Carna

Axinite-(Mg) is a borosilicate mineral of aluminum, calcium and magnesium of the axinite group, with magnesium as the dominant cation in the place of the structure that can also be occupied by iron and manganese. It was discovered in gem material from Merelani Hills, Lelatema Mts, Manyara Region, Tanzania, which is consequently its type locality. It was initially called magnesioaxinite, referring to its membership in the axinite group and the role of magnesium as the dominant cation. The International Mineralogical Association (IMA) later changed its name to axinite-(Mg). Occasionally it has b

type of fossil