Fraipontite

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Fraipontite
Fraipontite-sea52a.jpg
Pockets of minute pearly white fraipontite crystals with green smithsonite from Laurium, Greece (size: 1.4 x 1.0 x 0.9 cm)
General
Category Phyllosilicate
Formula
(repeating unit)
(Zn,Al)3(Si,Al)2O5(OH)4
IMA symbol Fpt [1]
Strunz classification 9.ED.15
Crystal system Monoclinic
Crystal class Domatic (m)
(same H-M symbol)
Space group Cm
Unit cell a = 5.34, b = 9.21
c = 14.12 [Å]; β = 93.2°; Z = 2
Identification
ColorBlueish, yellow white light green
Crystal habit Fibrous to porcelaneous massive
Mohs scale hardness3.5 – 4
Luster Silky
Streak White to pale green
Diaphaneity Opaque to translucent
Specific gravity 3.08 – 3.10
Optical propertiesBiaxial (-)
Refractive index nα = 1.620 nβ = 1.624 nγ = 1.624
Birefringence δ = 0.004
2V angle Measured: 15° to 20°
References [2] [3] [4]

Fraipontite is a zinc aluminium silicate mineral with a formula of (Zn,Al)3(Si,Al)2O5(OH)4. [2] [3]

It is a member of the kaolinite-serpentine mineral group and occurs as an oxidation product of zinc deposits. It occurs with smithsonite, gebhardite, willemite, cerussite and sauconite. [2]

It was first described in 1927 for an occurrence in Vieille Montagne, Verviers, Liège Province, Belgium. [3] It was named for Julien Jean Joseph Fraipont (1857–1910), and Charles de Fraipont, geologists of Liege, Belgium. [4] In addition to the type locality in Belgium, it has been reported from Tsumeb, Namibia; Laurium, Greece; Swaledale, North Yorkshire, England; the Silver Bill mine, Cochise County, Arizona, the Blanchard Mine, Socorro County, New Mexico and the Mohawk mine, San Bernardino County, California in the US; and from the Ojuela mine, Mapimi, Durango, Mexico. [2]

A synonym of the fraipontite is the zinalsite, which was reported in 1956 for an occurrence in Kazakhstan. [5] [6]

Related Research Articles

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

Hemimorphite is the chemical compound Zn4(Si2O7)(OH)2·H2O, a component of mineral calamine. It is a silicate mineral which, together with smithsonite (ZnCO3), has been historically mined from the upper parts of zinc and lead ores. Both compounds were originally believed to be the same mineral and classified as calamine. In the second half of the 18th century, it was discovered that these two different compounds were both present in calamine. They closely resemble one another.

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

Germanite is a rare copper iron germanium sulfide mineral, Cu26Fe4Ge4S32. It was first discovered in 1922, and named for its germanium content. It is only a minor source of this important semiconductor element, which is mainly derived from the processing of the zinc sulfide mineral sphalerite. Germanite contains gallium, zinc, molybdenum, arsenic, and vanadium as impurities.

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

Hydrozincite, also known as zinc bloom or marionite, is a white carbonate mineral consisting of Zn5(CO3)2(OH)6. It is usually found in massive rather than crystalline form.

<span class="mw-page-title-main">Erythrite</span> Hydrated cobalt arsenate mineral

Erythrite or red cobalt is a secondary hydrated cobalt arsenate mineral with the formula Co
3
(AsO
4
)
2
•8H
2
O
. Erythrite and annabergite, chemical formula Ni
3
(AsO
4
)
2
•8H
2
O
, or nickel arsenate form a complete series with the general formula (Co,Ni)
3
(AsO
4
)
2
•8H
2
O
.

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

Wurtzite is a zinc and iron sulfide mineral with the chemical formula (Zn,Fe)S, a less frequently encountered structural polymorph form of sphalerite. The iron content is variable up to eight percent. It is trimorphous with matraite and sphalerite.

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

Adamite is a zinc arsenate hydroxide mineral, Zn2AsO4OH. It is a mineral that typically occurs in the oxidized or weathered zone above zinc ore occurrences. Pure adamite is colorless, but usually it possess yellow color due to Fe compounds admixture. Tints of green also occur and are connected with copper substitutions in the mineral structure. Olivenite is a copper arsenate that is isostructural with adamite and there is considerable substitution between zinc and copper resulting in an intermediate called cuproadamite. Zincolivenite is a recently discovered mineral being an intermediate mineral with formula CuZn(AsO4)(OH). Manganese, cobalt, and nickel also substitute in the structure. An analogous zinc phosphate, tarbuttite, is known.

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

Gahnite, ZnAl2O4, is a rare mineral belonging to the spinel group. It forms octahedral crystals which may be green, blue, yellow, brown or grey. It often forms as an alteration product of sphalerite in altered massive sulphide deposits such as at Broken Hill, Australia. Other occurrences include Falun, Sweden where it is found in pegmatites and skarns; and, in the United States, Charlemont, Massachusetts; Spruce Pine, North Carolina; White Picacho district, Arizona; Topsham, Maine; and Franklin, New Jersey.

Weissite is a telluride mineral, a copper telluride. Its chemical formula is Cu
2−x
Te
. Weissite has hexagonal crystal structure. Its specific gravity is 6 and its Mohs hardness is 3. Occurrence is in Gunnison County, Colorado, Arizona and New Mexico in the United States. It is also reported from Kalgoorlie, Western Australia and Dalarna and Värmland, Sweden.

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

Zincochromite is a zinc chromium oxide mineral with the formula ZnCr2O4. It is the zinc analogue of chromite, hence the name. It was first described in 1987 as an occurrence in a uranium deposit near Lake Onega, Russia. It has also been reported from Dolo Hill, New South Wales, Australia, and from the Tarkwa Mine in the Ashanti gold belt of Ghana.

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

Legrandite is a rare zinc arsenate mineral, Zn2(AsO4)(OH)·(H2O).

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

Clinohedrite is a rare silicate mineral. Its chemical composition is a hydrous calcium-zinc silicate; CaZn(SiO4)·H2O. It crystallizes in the monoclinic system and typically occurs as veinlets and fracture coatings. It is commonly colorless, white to pale amethyst in color. It has perfect cleavage and the crystalline habit has a brilliant luster. It has a Mohs hardness of 5.5 and a specific gravity of 3.28 - 3.33.

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

Aliettite is a complex phyllosilicate mineral of the smectite group with a formula of (Ca0.2Mg6(Si,Al)8O20(OH)4·4H2O) or [Mg3Si4O10(OH)2](Ca0.5,Na)0.33(Al,Mg,Fe2+)2-3(Si,Al)4O10(OH)2·n(H2O).

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

Ordoñezite or ordóñezite is a rare tetragonal zinc antimonate mineral with chemical formula: ZnSb2O6.

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

Xocomecatlite is a rare tellurate mineral with formula: Cu3(TeO4)(OH)4. It is an orthorhombic mineral which occurs as aggregates or spherules of green needlelike crystals.

Chaidamuite is a rare zinc – iron sulfate mineral with chemical formula: ZnFe3+(SO4)2(OH)·4H2O.

<span class="mw-page-title-main">Stillwellite-(Ce)</span>

Stillwellite-(Ce) is a rare-earth boro-silicate mineral with chemical formula (Ce,La,Ca)BSiO5.

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

Amesite is a mineral with general formula of Mg2Al2SiO5(OH)4.

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

Utahite is an extremely rare secondary copper zinc tellurate mineral found as a product of oxidation. Its chemical formula is Cu5Zn3(Te6+O4)4(OH)8•7H2O.

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

Hemihedrite is a rare lead zinc chromate silicate mineral with formula Pb10Zn(CrO4)6(SiO4)2(F,OH)2. It forms a series with the copper analogue iranite.

Xitieshanite is a hydrous iron sulfate–chloride mineral with chemical formula: Fe3+(SO4)Cl·6(H2O).

References

  1. 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.
  2. 1 2 3 4 Handbook of Mineralogy
  3. 1 2 3 Mindat.org
  4. 1 2 Webmineral data for fraipontite
  5. Zinalsite on Webmineral
  6. Zinalsite on Mindat

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