Penikisite

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Penikisite
General
CategoryPhosphate mineral
Bjarebyite group
Formula
(repeating unit)		Ba(Mg,Fe,Ca)Al2(PO4)2(OH)3
IMA symbol Pks [1]
Strunz classification 8.BH.20
Crystal system Monoclinic
Space group P21/m
Identification
References [2] [3]

Penikisite was discovered by Alan Kulan and Gunar Penikis near Rapid Creek, Yukon Territory. The mineral is a member of the bjarebyite group along with kulanite, ideally BaFe2+2Al2(PO4)3(OH)3, and bjarebyite, ideally BaMn2+2Al2(PO4)3(OH)3. [4] It is among several new minerals that have been discovered in the Rapid Creek and Big Fish areas of Yukon Territory. Kulanite is similar in many ways to penikisite in appearance and properties. The chemical formula for penikisite is Ba(Mg,Fe,Ca)Al2(PO4)2(OH)3. [5] It has a hardness of about 4 and a density of 3.79 g/cm3. [5] Penikisite is unique among the bjarebyite group in being monoclinic [6] and has a biaxial optical class. [7] It comes in shades of blue and green and, when rubbed on a streak plate, is pale green to white in color. [5] Although penikisite and kulanite both range from blue to green, penikisite zones are easily distinguishable from kulanite zones in kulanite-penikisite crystals because they are lighter than the darker kulanite in color. [5] Penikisite is a phosphate and is different from kulanite in that it is a magnesium-rich phosphate whereas kulanite is an iron-rich phosphate. [5]

Contents

Introduction

Penikisite, ideally Ba(Mg,Fe,Ca)Al2(PO4)2(OH)3, is a second occurrence of kulanite. [5] Both kulanite and penikisite are members of the bjarebyite group. [4] Minerals in the bjarebyite group have the general formula XY2Z2(PO4)3(OH)3 where X=Ba, Y=Mg,Fe2+,Mn2+, and Z=Al,Fe3+. [8] Penikisite was found in a Yukon phosphate deposit near Rapid Creek. The mineral, along with kulanite, occurs in an iron-formation. [9] In these iron-formations, Mg-rich zones were discovered and named penikisite in honor of Gunar Penikis who discovered these phosphate occurrences with Alan Kulan. [5]

Composition

The chemical formula of penikisite is Ba(Mg,Fe,Ca)Al2(PO4)2(OH)3. [5] Mandarino and Sturman analyzed two penikisite samples and eight kulanite samples using an AMX electron miscroprobe (1977). Their study showed weight percent oxides, including H2O, that help determine what the formula is for penikisite and kulanite. Members of the bjarebyite group have the general formula XY2Z2(PO4)3(OH)3 where X=Ba, Y=Mg,Fe(2+),Mn(2+), and Z=Al,Fe3+. [8] Accompanying penikisite in this group are as follows: bjarebyite, ideally BaMn2+2Al2(PO4)3(OH)3, perloffite, ideally BaMn2+2Fe3+2(PO4)3(OH)3, kulanite, BaFe2+2Al2(PO4)3(OH)3, and johntomaite, ideally BaFe2+2Fe3+2(PO4)3(OH)3. [4] These minerals are identified when Ba in the X position is one of the most abundant elements in their composition along with being phosphates. [8]

Physical properties

Penikisite ranges from blue to green with a vitreous luster and, when rubbed along a streak plate, can be pale green to white. Depending on the thickness of the sample, the mineral can be either transparent or translucent. [5] Penikisite is monoclinic with space group P21/m. [3] The cell dimensions of this mineral were calculated by Mandarino and Sturman (1977) by least-squares refinement of the X-ray powder diffraction data to be: a 8.999, b 12.069, c 4.921Å. The mineral is non-fluorescent under short- and long-waves. It has a harness of about 4 and a density of 3.79(2) g/cm3. There are two fair to good cleavages on {010} and {100}. Penikisite is biaxial (+) with nα 1.684(2), nβ 1.688(2), nγ 1.705(2). The 2V(γ) calculation is 56° and the 2V measurement is 52.2°. The pleochroism for penikisite is X grass-green, Y blue-green, Z pale pink. The absorption is X~Y>Z. [5]

Geologic occurrence

In recent years, Rapid Creek, in the northeastern corner of Yukon Territory, has become more popular in the mineralogist community. This is because of the large deposit of phosphate minerals that have been discovered in the area. [9] Texturally, the rocks of Rapid Creek are similar to other Phanerozoic phosphate and iron deposits; they are composed of pellets and granules, detrital quarts grains, skeletal fragments, and siderite mud matrix. [9] Discovered in phosphate-ironstones that crop out near Rapid Creek, penikisite and kulanite occurs in fractures in a sideritic iron-formation. [8]

Related Research Articles

<span class="mw-page-title-main">Pyroxene</span> Group of inosilicate minerals with single chains of silica tetrahedra

The pyroxenes are a group of important rock-forming inosilicate minerals found in many igneous and metamorphic rocks. Pyroxenes have the general formula XY(Si,Al)2O6, where X represents calcium (Ca), sodium (Na), iron or magnesium (Mg) and more rarely zinc, manganese or lithium, and Y represents ions of smaller size, such as chromium (Cr), aluminium (Al), magnesium (Mg), cobalt (Co), manganese (Mn), scandium (Sc), titanium (Ti), vanadium (V) or even iron. Although aluminium substitutes extensively for silicon in silicates such as feldspars and amphiboles, the substitution occurs only to a limited extent in most pyroxenes. They share a common structure consisting of single chains of silica tetrahedra. Pyroxenes that crystallize in the monoclinic system are known as clinopyroxenes and those that crystallize in the orthorhombic system are known as orthopyroxenes.

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

Vivianite (Fe2+
3(PO
4)
2·8H
2O) is a hydrated iron phosphate mineral found in a number of geological environments. Small amounts of manganese Mn2+, magnesium Mg2+, and calcium Ca2+ may substitute for iron Fe2+ in the structure. Pure vivianite is colorless, but the mineral oxidizes very easily, changing the color, and it is usually found as deep blue to deep bluish green prismatic to flattened crystals.
Vivianite crystals are often found inside fossil shells, such as those of bivalves and gastropods, or attached to fossil bone.

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

Lazulite ((Mg,Fe2+)Al2(PO4)2(OH)2) is a blue, phosphate mineral containing magnesium, iron, and aluminium phosphate. Lazulite forms one endmember of a solid solution series with the darker iron rich scorzalite.

<span class="mw-page-title-main">Phosphate mineral</span> Nickel–Strunz 9 ed mineral class number 8 (isolated tetrahedral units, mainly)

Phosphate minerals contain the tetrahedrally coordinated phosphate (PO43−) anion, sometimes with arsenate (AsO43−) and vanadate (VO43−) substitutions, along with chloride (Cl−), fluoride (F−), and hydroxide (OH−) anions, that also fit into the crystal structure.

<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">Scorzalite</span>

Scorzalite ((Fe2+,Mg)Al2(OH,PO4)2) is a dark blue phosphate mineral containing iron, magnesium, and aluminium phosphate. Scorzalite forms one endmember of a solid solution series with the lighter, more magnesium-rich lazulite.

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

Alluaudite is a relatively common alkaline manganese iron phosphate mineral with the chemical formula (Na,Ca)Mn2+(Fe3+,Mn2+,Fe2+,Mg)2(PO4)3. It occurs as metasomatic replacement in granitic pegmatites and within phosphatic nodules in shales.

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

Hureaulite is a manganese phosphate with the formula Mn2+5(PO3OH)2(PO4)2·4H2O. It was discovered in 1825 and named in 1826 for the type locality, Les Hureaux, Saint-Sylvestre, Haute-Vienne, Limousin, France. It is sometimes written as huréaulite, but the IMA does not recommend this for English language text.

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

Lulzacite is a strontium-containing phosphate mineral with the chemical formula Sr2Fe2+(Fe2+,Mg)2Al4(PO4)4(OH)10.

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


Gormanite is a phosphate mineral with the formula (Fe,Mg)3Al4(PO4)4(OH)6·2H2O. It was named after the University of Toronto professor Donald Herbert Gorman (1922–2020).

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">Whiteite</span>

Whiteite is a rare hydrated hydroxyphosphate mineral.

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

Maricite or marićite is a sodium iron phosphate mineral (NaFe2+PO4), that has two metal cations connected to a phosphate tetrahedron. It is structurally similar to the much more common mineral olivine. Maricite is brittle, usually colorless to gray, and has been found in nodules within shale beds often containing other minerals.

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

Satterlyite is a hydroxyl bearing iron phosphate mineral. The mineral can be found in phosphatic shales and was first discovered in the Big Fish River area in Yukon Territory, Canada.

Falsterite is a rare phosphate mineral with the formula Ca2MgMn2+2(Fe2+0.5Fe3+0.5)4Zn4(PO4)8(OH)4(H2O)14. It is a pegmatitic mineral, related to the currently approved mineral ferraioloite.

Ferraioloite is a rare mineral with formula MgMn2+4(Fe2+0.5Al0.5)4Zn4(PO4)8(OH)4(H2O)20. It is related to the phosphate mineral falsterite. Ferraioloite was found in pegmatites of the Foote Lithium Company Mine, Cleveland County, North Carolina, US. The name honors James (Jim) A. Ferraiolo (1947–2014).

Fluorcarmoite-(BaNa) is a rare phosphate mineral, belonging to arrojadite group, with the formula Ba[]Na2Na2[]CaMg13Al(PO4)11(PO3OH)F2. It is a barium-rich member of the group, as is arrojadite-(BaNa), arrojadite-(BaFe), fluorarrojadite-(BaFe) and an unapproved species ferri-arrojadite-(BaNa). The "-(BaNa)" suffix informs about the dominance of the particular elements (here barium and sodium) at the corresponding structural sites.

Manganese phosphate may refer to:

References

  1. ↑ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. doi: 10.1180/mgm.2021.43 . S2CID   235729616.
  2. ↑ Mineralienatlas
  3. 1 2 Bowman, Michael G.; Downs, Robert T.; Yang, Hexiong (15 February 2013). "Penikisite, BaMg 2 Al 2 (PO 4 ) 3 (OH) 3 , isostructural with bjarebyite". Acta Crystallographica Section E. 69 (2): i4–i5. doi: 10.1107/S1600536812051793 . PMC   3569169 . PMID   23424395.
  4. 1 2 3 Elliott, P. & Willis A.C., ["The crystal structure of perloffite"], Mineralogical Magazine, 2011
  5. 1 2 3 4 5 6 7 8 9 10 Mandarino, J.A., Sturman, B.D. & Corlett, M.I., ["Penikisite, the magnesium analogue of kulanite, from the Yukon Territory"], Can. Mineral, 1977
  6. ↑ Bowman, Downs & Yang 2013.
  7. ↑ Anthony, John W., Richard A., Kenneth W. and Nichols, Monte C. Eds., ["Penikisite"], Handbook of Mineralogy, Mineralogical Society of America, Chantilly, VA, 2001–2005
  8. 1 2 3 4 Cooper M. & Hawthorne F.C., ["Refinement of the crystal structure of kulanite"], Can. Mineral, 1994
  9. 1 2 3 Robertson, B.T. ["Occurrence of epigenetic phosphate minerals in a phosphatic iron-formation, Yukon Territory"], Mineral. Rec., 1982
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