Plagioclase ( PLAJ-(ee)-ə-klayss, PLAYJ-, -klayz) is a series of tectosilicate (framework silicate) minerals within the feldspar group. Rather than referring to a particular mineral with a specific chemical composition, plagioclase is a continuous solid solution series, more properly known as the plagioclase feldspar series. This was first shown by the German mineralogist Johann Friedrich Christian Hessel (1796–1872) in 1826. The series ranges from albite to anorthite endmembers (with respective compositions NaAlSi3O8 to CaAl2Si2O8), where sodium and calcium atoms can substitute for each other in the mineral's crystal lattice structure. Plagioclase in hand samples is often identified by its polysynthetic crystal twinning or "record-groove" effect.
CharoiteK(Ca,Na)
2Si
4O
10(OH,F)•H
2O is a rare silicate mineral, first described in 1978. It is named after the Chara River, despite its being 70 km away from the discovery place; the name of the river translated from Evenki means “to melt, melt.” When it was discovered, it was thought to be a fake, dyed purple to give it its striking appearance.
Mckelveyite-(Y) is a hydrated sodium, barium, yttrium, and uranium–containing carbonate mineral, with the chemical formula Ba3Na(Ca,U)Y(CO3)6·3H2O.
Brammallite is a sodium rich analogue of illite. First described in 1943 for an occurrence in Llandybie, Carmarthenshire, Wales, it was named for British geologist and mineralogist Alfred Brammall (1879–1954).
Yuksporite is a rare inosilicate mineral with double width, unbranched chains, and the complicated chemical formula K4(Ca,Na)14Sr2Mn(Ti,Nb)4(O,OH)4(Si6O17)2(Si2O7)3(H2O,OH)3. It contains the relatively rare elements strontium, titanium and niobium, as well as the commoner metallic elements potassium, calcium, sodium and manganese. As with all silicates, it contains groups of linked silicon and oxygen atoms, as well as some associated water molecules.
Tinaksite (chemical formula K2Na(Ca,Mn2+)2TiO[Si7O18(OH)]) 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.
Frankamenite is the fluorine-dominate variation of the rare mineral canasite with a general formula of K3Na3Ca5(Si12O30)[F,(OH)]4·(H2O).
Eveslogite is a complex inosilicate mineral with a chemical formula (Ca,K,Na,Sr,Ba)
48[(Ti,Nb,Fe,Mn)
12(OH)
12Si
48O
144](F,OH,Cl)
14 found on Mt. Eveslogchorr in Khibiny Mountains, on the Kola peninsula, Russia. It was named after the place it was found. This silicate mineral occurs as an anchimonomineral veinlet that cross-cuts poikilitic nepheline syenite. This mineral appears to resemble yuksporite, as it forms similar placated fine fibrous of approximately 0.05 to 0.005mm that aggregates outwardly. The color of eveslogite is yellow or rather light brown. In addition, it is a semitransparent mineral that has a white streak and a vitreous luster. Its crystal system is monoclinic and possesses a hardness (Mohs) of 5. This newly discovered mineral belongs to the astrophyllite group of minerals and contains structures that are composed of titanosilicate layers. Limited information about this mineral exists due to the few research studies carried out since its recent discovery.
Andrianovite is a very rare mineral of the eudialyte group, with formula Na12(K,Sr,Ce)6Ca6(Mn,Fe)3Zr3NbSi(Si3O9)2(Si9O27)2O(O,H2O,OH)5. The original formula was extended to show the presence of cyclic silicate groups and silicon at the M4 site, according to the nomenclature of eudialyte group. Andrianovite is unique among the eudialyte group in being potassium-rich (other eudialyte-group species with essential K are davinciite and rastsvetaevite). It is regarded as potassium analogue of kentbrooksite, but it also differs from it in being oxygen-dominant rather than fluorine-dominant. Also, the coordination number of Na in this representative is enlarged from 7 to 9. The name of the mineral honors Russian mathematician and crystallographer Valerii Ivanovich Andrianov.
Georgbarsanovite is a very rare mineral of the eudialyte group, formerly known under unaccepted name as barsanovite, with formula Na12(Mn,Sr,REE)3Ca6Fe32+Zr3NbSi(Si3O9)2(Si9O27)2O4Cl2·H2O. The original formula was extended to show the presence of cyclic silicate groups and the domination of silicon at the M4 site. "REE", standing for rare earth elements, is dominated by cerium. Georgbarsanovite is characterized in dominance of manganese at the N4 site. It also differs from most other accepted group representatives in its colour. The mineral was found in nepheline pegmatite near Petrelius River, Khibiny massif, Kola Peninsula, Russia. It is named after Russian mineralogist Georg Barsanov.
Rastsveatevite is a rare mineral of the eudialyte group with the chemical formula Na27K8Ca12Fe3Zr6Si4[Si3O9]4[Si9O27]4(O,OH,H2O)6Cl2. Its structure is modular. It is only the third member of the group after andrianovite and davinciite with essential (site-dominating) potassium. Potassium and sodium enter both N4 and M2 sites. The mineral is named after Russian crystallographer Ramiza K. Rastsvetaeva.
Fluorcanasite is a rare calcium, potassium, sodium fluoride silicate mineral, discovered in the Kirovsk mine's dumps, in Russia. It has been approved by the IMA in 2007. The name fluorcanasite is a portmanteau word, and was made by blending fluorine, a chemical element that can be found in the mineral, and canasite, as the mineral is close to canasite in several ways. Fluorcanasite is also close to frankamenite.
Ganophyllite is a phyllosilicate mineral. It was named by Axel Hamberg in 1890 from the Greek words for leaf (φύλλον) and luster (γανωμα); the latter one was chosen due to the lustrous cleavages. The mineral was approved by the IMA in 1959, and it is a grandfathered mineral, meaning its name is still believed to refer to an existing species until this day. Tamaite is the calcium analogue, while eggletonite is the natrium analogue of said mineral.
Hendricksite is a member of the trioctahedral micas group. The mineral was named by Clifford Frondel and Jun Ito in honor of Sterling Brown Hendricks, who studied micas. It was approved in 1966 by the IMA.
Baratovite is a very rare cyclosilicate mineral named after Rauf Baratovich Baratov from Tajikistan. It was discovered in 1974 at Dara-Pioz glacier, Tajikistan, and was approved by the International Mineralogical Association only a year later in 1975. The glacier gives home to 133 valid species, and is the type locality of 33 minerals, one of which is baratovite.
Katayamalite is a cyclosilicate mineral that was named in honor of mineralogist and professor Nobuo Katayama. It was approved in 1982 by the International Mineralogical Association, and was first published a year later.
Bannisterite is a mineral named in honor of mineralogist and x-ray crystallographer Dr. Frederick Allen Bannister (1901-1970). It is a calcium-dominant member of the ganophyllite group, and was previously identified as ganophyllite in 1936, but otherwise it is structurally related to the stilpnomelane group. It was approved by the IMA in 1967.
Murun is a mountain in the Olyokma-Chara Plateau, at the border of Irkutsk Oblast and Yakutia, Russian Federation.
Bavenite is a calcium beryllium aluminosilicate, and it is a part of the Bavenite-Bohseite series. Its name originates from its type locality, which is Baveno, Italy. This mineral is approved by the IMA, and got grandfathered, meaning it is still believed to refer to a valid mineral species. It was discovered in 1901 in a pink granite mined in Lago Maggiore. When bavenite was discovered, it was considered as a member of the zeolite series. Later it was removed from the series as unlike zeolites, bavenite loses the water stored in its crystal lattice in a way higher temperature, between 210 and 320 °C. It is a cheap mineral considering its rarity.
Olmiite is a rare calcium-manganese silicate that was named after an Italian mineralogist called Filippo Olmi. It was approved by the IMA in 2006, being first published in 2007, which makes it a relatively newly discovered mineral. Around 2001, a large amount of specimens believed to be poldervaartite was discovered at the N'Chwaning II mine, which is near the Wessels mine, where the latter was discovered. Only later were the researchers able to determine through their investigations that the two minerals are different, as they are visually indistinguishable. Until Renato Pagano acquired and examined the specimens, seemingly no specific investigation was carried out. Olmiite has been misidentified not only once, but twice. The cream-colored specimens were at first thought to be baryte by the mine geologist.
Radioactive 1.12% (K)