Leucophoenicite | |
---|---|
General | |
Category | Nesosilicates [1] |
Formula (repeating unit) | Mn7(SiO4)3(OH)2 |
IMA symbol | Lpo [2] |
Strunz classification | 9.AF.60 [1] |
Dana classification | 52.3.2c.2 [1] |
Crystal system | Monoclinic |
Crystal class | Prismatic (2/m) (same H-M symbol) |
Space group | P21/a |
Unit cell | a = 10.84 Å b = 4.82 Å c = 11.32 Å β = 103.93°; [1] Z = 2 |
Identification | |
Cleavage | Imperfect on {001} |
Tenacity | Brittle |
Mohs scale hardness | 5.5 to 6 |
Luster | Vitreous |
Diaphaneity | Transparent to translucent |
Optical properties | Biaxial (−) |
Refractive index | nα = 1.751 nβ = 1.771 nγ = 1.782 [1] |
Birefringence | δ = 0.031 [1] |
Pleochroism | Faint; rose-red ∥ {001} Colorless ⊥ {001} |
2V angle | 74° (measured) |
Ultraviolet fluorescence | Non-fluorescent [3] |
References | [4] |
Leucophoenicite is a mineral with formula Mn7(SiO4)3(OH)2. Generally brown to red or pink in color, the mineral gets its name from the Greek words meaning "pale purple-red". Leucophoenicite was discovered in New Jersey, US and identified as a new mineral in 1899.
Leucophoenicite is normally brown, light purple-red, raspberry-red or pink in color; in thin section it is rose-red to colorless. [4] The name is derived from the Greek words leukos, meaning "pale", and foinis, meaning "purple-red", in reference to its common coloring. [1] [3]
Leucophoenicite typically occurs as isolated grains or it has granular massive habit. Crystals of the mineral, which occur rarely, are slender, prismatic, elongated, and striated. [4] The mineral forms in a low pressure, hydrothermal environment or in a contact zone in the veins and skarns of a stratiform Zn-Mn ore body. [4] [5]
Leucophoenicite is a member of the humite group. [1] It has been found in association with barite, barysilite, calcite, copper, franklinite, garnet, glaucochroite, hausmannite, jerrygibbsite, manganosite, pyrochroite, rhodochrosite, sonolite, spessartine, sussexite, tephroite, vesuvianite, willemite, and zincite. [4]
Leucophoenicite was first found by J. J. McGovern at the Franklin Mine in New Jersey. The specimen, which consisted mostly of the mineral, was given to C. H. Warren in 1897. First thought to be clinohedrite deeply colored by manganese, it was identified as a new mineral in 1899 by Warren and Samuel Lewis Penfield. [6] The mineral was also discovered around this time from the Buckwheat Pit in New Jersey; [1] however, it was not identified as leucophoenicite until 1906 as it had been overlooked or mistaken for some other substance. [7]
The crystallography was first described by Charles Palache in 1910, as Penfield and Warren had been unable to determine even the crystal system of leucophoenicite. [6] [8] Material thought to be leucophoenicite, studied in 1928, 1935, and 1967, was in fact a composite of leucophoenicite, sonolite, and alleghanyite. [9] The specimens studied by Warren and Penfield in 1899 and Palache in 1910 were both true leucophoenicite. [10]
As of 2012 [update] , leucophoenicite has been found in Italy, Japan, Namibia, Romania, South Africa, Sweden, and the US. [1] The type material is held in the United States at Yale University and Harvard University. [4]
Lazurite, old name Azure spar is a tectosilicate mineral with sulfate, sulfur and chloride with formula (Na,Ca)8[(S,Cl,SO4,OH)2|(Al6Si6O24)]. It is a feldspathoid and a member of the sodalite group. Lazurite crystallizes in the isometric system although well‐formed crystals are rare. It is usually massive and forms the bulk of the gemstone lapis lazuli.
Bornite, also known as peacock ore, is a sulfide mineral with chemical composition Cu5FeS4 that crystallizes in the orthorhombic system (pseudo-cubic). It is an important copper ore.
Tephroite is the manganese endmember of the olivine group of nesosilicate minerals with the formula Mn2SiO4. A solid solution series exists between tephroite and its analogues, the group endmembers fayalite and forsterite. Divalent iron or magnesium may readily replace manganese in the olivine crystal structure.
Hardystonite is a rare calcium zinc silicate mineral first described from the Franklin, New Jersey, U.S. zinc deposits. It often contains lead, which was detrimental to the zinc smelting process, so it was not a useful ore mineral. Like many of the famous Franklin minerals, hardystonite responds to short wave ultraviolet light, emitting a fluorescence from dark purple to bright violet blue. In daylight, it is white to gray to light pink in color, sometimes with a vitreous or greasy luster. It is very rarely found as well formed crystals, and these are usually rectangular in appearance and rock-locked.
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 Taymyr region of northern Siberia. It is one of two humite group minerals that have been cut into gems, the other being the much more common chondrodite.
Lithiophilite is a mineral containing the element lithium. It is lithium manganese(II) phosphate with chemical formula LiMnPO4. 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 Li(Mn,Fe)PO4). The name lithiophilite is derived from the Greek philos (φιλός) "friend", as lithiophilite is usually found with lithium.
Chondrodite is a nesosilicate mineral with formula (Mg,Fe)
5(SiO
4)
2(F,OH,O)
2. Although it is a fairly rare mineral, it is the most frequently encountered member of the humite group of minerals. It is formed in hydrothermal deposits from locally metamorphosed dolomite. It is also found associated with skarn and serpentinite. It was discovered in 1817 at Pargas in Finland, and named from the Greek for "granule", which is a common habit for this mineral.
Galaxite, also known as 'mangan-spinel' is an isometric mineral belonging to the spinel group of oxides with the ideal chemical formula Mn2+Al2O4.
Breithauptite is a nickel antimonide mineral with the simple formula NiSb. Breithauptite is a metallic opaque copper-red mineral crystallizing in the hexagonal - dihexagonal dipyramidal crystal system. It is typically massive to reniform in habit, but is observed as tabular crystals. It has a Mohs hardness of 3.5 to 4 and a specific gravity of 8.23.
Jerrygibbsite is a rare silicate mineral with the chemical formula (Mn,Zn)9(SiO4)4(OH)2. Jerrygibbsite was originally discovered by Pete J. Dunn in 1984, who named it after mineralogist Gerald V. Gibbs. It has only been reported from the type locality of Franklin Furnace, New Jersey, United States, and in Namibia's Otjozondjupa region. Jerrygibbsite is member of the leucophoenite family of the humite group. It is always found with these two minerals. It is a dimorph of sonolite.
Hodgkinsonite is a rare zinc manganese silicate mineral Zn2MnSiO4(OH)2. It crystallizes in the monoclinic system and typically forms radiating to acicular prismatic crystals with variable color from pink, yellow-red to deep red. Hodgkinsonite was discovered in 1913 by H. H. Hodgkinson, for whom it is named in Franklin, New Jersey, and it is only found in that area.
Allactite is a rare arsenate mineral of metamorphosed manganese zinc ore deposits. It is found in Sweden and New Jersey, US. Its name originated from Greek αλλάκτειν (allaktein) meaning "to change", referring to the strong pleochroism of the mineral.
Alleghanyite is a moderately rare humite mineral with formula Mn5(SiO4)2(OH)2, belonging to the nesosilicates class. In general its occurrences are related with metamorphic (metamorphosed) manganese deposits. The mineral is named after Alleghany County, North Carolina, US.
The humite group is a group of nesosilicates with the general formula An(SiO4)m(F,OH)2.
Hambergite (Be2BO3OH) is a beryllium borate mineral named after Swedish explorer and mineralogist Axel Hamberg (1863–1933). The mineral occurs as white or colorless orthorhombic crystals.
Sonolite is a mineral with formula Mn9(SiO4)4(OH,F)2. The mineral was discovered in 1960 in the Sono mine in Kyoto Prefecture, Japan. In 1963, it was identified as a new mineral and named after the Sono mine.
Diaboleite is a blue-colored mineral with formula Pb2CuCl2(OH)4. It was discovered in England in 1923 and named diaboleite, from the Greek word διά and boleite, meaning "distinct from boleite". The mineral has since been found in a number of countries.
Charlesite is a sulfate mineral of the ettringite group. Charlesite was named in 1945 after Dr. Charles Palache mineralogist and professor at Harvard University for his work on minerals. This mineral is extremely rare, and when it is found it is often in crystal form. Its crystals are soft hexagonal, that can vary in color. Colors can range from clear to white, or even a pale yellow or pink. The brittle mineral's Mohs hardness is 2.5 with a specific gravity of 1.79. Though transparent to the eye the mineral has a white streak.
Charles Palache was an American mineralogist and crystallographer. In his time, he was one of the most important mineralogists in the United States.