Epidote group

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Epidote group
Epidote Madagascar.jpg
General
Category Sorosilicates
Formula
(repeating unit)
(A2+1A2+2)(M3+1M3+2M3+3)O[Si2O7][SiO4](OH)
IMA symbol Ep
Crystal system Monoclinic
Crystal class Prismatic (2/m)
(same H–M symbol)
Space group P21/m
Identification
ColorYellow-green, pistachio green, greenish black, brownish-green, green, black
Crystal habit Prismatic, fibrous, druse/encrustation, massive
Twinning On [100]
Cleavage {001} perfect and {100} imperfect
Mohs scale hardness6–7
Luster Vitreous

Epidotes are a group of sorosilicate minerals that are common in igneous and metamorphic rocks. [1] [2] [3]

Epidote member species

Related Research Articles

<span class="mw-page-title-main">Zoisite</span> Sorosilicate mineral

Zoisite, first known as saualpite, after its type locality, is a calcium aluminum hydroxy sorosilicate belonging to the epidote group of minerals. Its chemical formula is Ca2Al3(SiO4)(Si2O7)O(OH).

<span class="mw-page-title-main">Epidote</span> Sorosilicate mineral

Epidote is a calcium aluminium iron sorosilicate mineral.

<span class="mw-page-title-main">Silicate mineral</span> Rock-forming minerals with predominantly silicate anions

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.

<span class="mw-page-title-main">Allanite</span> Rare-earth enriched sorosilicate mineral

Allanite (also called orthite) is a sorosilicate group of minerals within the broader epidote group that contain a significant amount of rare-earth elements. The mineral occurs mainly in metamorphosed clay-rich sediments and felsic igneous rocks. It has the general formula A2M3Si3O12[OH], where the A sites can contain large cations such as Ca2+, Sr2+, and rare-earth elements, and the M sites admit Al3+, Fe3+, Mn3+, Fe2+, or Mg2+ among others. However, a large amount of additional elements, including Th, U, Be, Zr, P, Ba, Cr and others may be present in the mineral. The International Mineralogical Association lists four minerals in the allanite group, each recognized as a unique mineral: allanite-(Ce), allanite-(La), allanite-(Nd), and allanite-(Y), depending on the dominant rare earth present: cerium, lanthanum, neodymium or yttrium.

<span class="mw-page-title-main">Braunite</span> Nesosilicate mineral of manganese

Braunite is a silicate mineral containing both di- and tri-valent manganese with the chemical formula: Mn2+Mn3+6[O8|SiO4]. Common impurities include iron, calcium, boron, barium, titanium, aluminium, and magnesium.

<span class="mw-page-title-main">Clinozoisite</span>

Clinozoisite is a complex calcium aluminium sorosilicate mineral with formula: Ca2Al3(Si2O7)(SiO4)O(OH). It forms a continuous solid solution series with epidote by substitution of iron(III) in the aluminium (m3 site) and is also called aluminium epidote.

<span class="mw-page-title-main">Lawsonite</span>

Lawsonite is a hydrous calcium aluminium sorosilicate mineral with formula CaAl2Si2O7(OH)2·H2O. Lawsonite crystallizes in the orthorhombic system in prismatic, often tabular crystals. Crystal twinning is common. It forms transparent to translucent colorless, white, pink, and bluish to pinkish grey glassy to greasy crystals. Refractive indices are nα = 1.665, nβ = 1.672 – 1.676, and nγ = 1.684 – 1.686. It is typically almost colorless in thin section, but some lawsonite is pleochroic from colorless to pale yellow to pale blue, depending on orientation. The mineral has a Mohs hardness of 7.5 and a specific gravity of 3.09. It has perfect cleavage in two directions and a brittle fracture. Not to be confused with Larsonite, a fossiliferous jasper mined in Nevada.

<span class="mw-page-title-main">Pumpellyite</span> Pumpellyite series

Pumpellyite is a group of closely related sorosilicate minerals:

<span class="mw-page-title-main">Robertsite</span> Phosphate mineral

Robertsite, Ca3(Mn3+)4[(OH)3| (PO4)2]2·3(H2O) (alternatively formulated Ca2(Mn3(PO4)3O2)(H2O)3), is a secondary phosphate mineral named for Willard Lincoln Roberts (1923–1987), mineralogist and professor at South Dakota School of Mines in Rapid City, South Dakota.

<span class="mw-page-title-main">Julgoldite</span> Silicate mineral

Julgoldite is a member of the pumpellyite mineral series, a series of minerals characterized by the chemical bonding of silica tetrahedra with alkali and transition metal cations. Julgoldites, along with more common minerals like epidote and vesuvianite, belong to the subclass of sorosilicates, the rock-forming minerals that contain SiO4 tetrahedra that share a common oxygen to form Si2O7 ions with a charge of 6− (Deer et al., 1996). Julgoldite has been recognized for its importance in low grade metamorphism, forming under shear stress accompanied by relatively low temperatures (Coombs, 1953). Julgoldite was named in honor of Professor Julian Royce Goldsmith (1918–1999) of the University of Chicago.

<span class="mw-page-title-main">Piemontite</span>

Piemontite is a sorosilicate mineral in the monoclinic crystal system with the chemical formula Ca2(Al,Mn3+,Fe3+)3(SiO4)(Si2O7)O(OH). It is a member of the epidote group.

<span class="mw-page-title-main">Dollaseite-(Ce)</span> Epidote supergroup, sorosilicate mineral

Dollaseite-(Ce) is a sorosilicate end-member epidote rare-earth mineral which was discovered by Per Geijer (1927) in the Ostanmossa mine, Norberg district, Sweden. Dollaseite-(Ce), although not very well known, is part of a broad epidote group of minerals which are primarily silicates, the most abundant type of minerals on earth. Dollaseite-(Ce) forms as dark-brown subhedral crystals primarily in Swedish mines. With the ideal chemical formula, CaREE3+
Mg
2
AlSi
3
O
11
,(OH)F
, dollaseite-(Ce) can be partially identified by its content of the rare earth element cerium.

Cleusonite is a member of the crichtonite group of minerals with the chemical formula (Pb,Sr)(U4+
,U6+
)(Fe2+
,Zn)
2
(Ti,Fe2+
,Fe3+
)
18
(O,OH)
38
. This group of minerals contains approximately thirteen complex metal titanates. The structures of minerals of this group is complicated by frequent fine-scale twinning and metamictization due to radioactive elements. The crichtonite group consists of members of related mineral species of the type A{BC2D6E12}O38 which are characterized by their predominant cations (as seen in crichtonite (Sr), senaite (Pb), davidite (REE + U), landauite (Na), loveringite (Ca), lindsleyite (Ba), and mathiasite (K).

This list gives an overview of the classification of non-silicate minerals and includes mostly International Mineralogical Association (IMA) recognized minerals and its groupings. This list complements the List of minerals recognized by the International Mineralogical Association series of articles and List of minerals. Rocks, ores, mineral mixtures, not IMA approved minerals, not named minerals are mostly excluded. Mostly major groups only, or groupings used by New Dana Classification and Mindat.

This list gives an overview of the classification of minerals (silicates) and includes mostly International Mineralogical Association (IMA) recognized minerals and its groupings. This list complements the List of minerals recognized by the International Mineralogical Association series of articles and List of minerals. Rocks, ores, mineral mixtures, non-IMA approved minerals and non-named minerals are mostly excluded.

<span class="mw-page-title-main">Manganvesuvianite</span>

Manganvesuvianite is a rare mineral with formula Ca19Mn3+(Al,Mn3+,Fe3+)10(Mg,Mn2+)2(Si2O7)4(SiO4)10O(OH)9. The mineral is red to nearly black in color. Discovered in South Africa and described in 2002, it was so named for the prevalence of manganese in its composition and its relation to vesuvianite.

<span class="mw-page-title-main">Gugiaite</span>

Gugiaite is a melilite mineral, named for the Chinese village of Gugia where it was first discovered. Its chemical formula is Ca2BeSi2O7. It occurs mostly in skarns with melanite adjacent to an alkali syenite and has no economic value. Its crystals are small tetragonal tablets with vitreous luster and perfect cleavage. It is colorless and transparent with a density of three. The mineral belongs to space group P421m and is strongly piezoelectric.

<span class="mw-page-title-main">Lamprophyllite</span> Ti-silicate mineral

Lamprophyllite is a rare, but widespread mineral Ti-silicate mineral usually found in intrusive agpasitic igneous rocks. Yellow, reddish brown, Vitreous, Pearly.

References

  1. Armbruster, T.; Bonazzi, P.; Akasaka, M.; Bermanec, V.; Chopin, C.; Gieré, R.; Heuss-Assbichler, S.; Liebscher, A.; Menchetti, S.; Pan, Y.; Pasero, M. (2006). "Recommended nomenclature of epidote-group minerals". European Journal of Mineralogy. 18 (5): 551−567. Bibcode:2006EJMin..18..551A. doi: 10.1127/0935-1221/2006/0018-0551 .
  2. Kartashov, P. M. (2014). "Classification diagram for REE-bearing members of the epidote group based on crystallochemical data". Proceedings of the Workshop on Acessory Minerals: 25−26.
  3. Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi: 10.1180/mgm.2021.43 . S2CID   235729616.