Heftetjern pegmatite, Tørdal, Drangedal, Telemark, Norway (original) (raw)

Description: In light green fibrous and porous masses 2-3 mm across, cascandite has been found as intimate fibrous intergrowths of scandiobabingtonite (areas of intergrowths exceeding 100my in length (Raade & Erambert 1999)

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ⓘ Cassiterite

Formula: SnO2

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ⓘ Cerussite

Formula: PbCO3

ⓘ Clinochlore

Formula: Mg5Al(AlSi3O10)(OH)8

ⓘ Epidote

Formula: (CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH)

Description: A cerian variety

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ⓘ 'Epidote Group'

Formula: (A12+A22+)(M13+M23+M33+)O[Si2O7][SiO4](OH)

Habit: Grey, Greyish-browb, reddish to brownish

Description: At Heftetjern epidote goup minerals appear as mm-sized plate-like, transparent crystals in in aggregates, and in varying colours. Premlininary studies revealed that these are scandian or cerian epidotes. They are complex zonated, showing different chemistry of the epidote – allanite-(Ce) solid-solution series in the diffent zones in one single crystal. Zonated crystals with 8,3 wt% Sc2O3 has been found.

References:

**Pieczka, Adam, Kristiansen, Roy, Stachowicz, Marcin, Dumańska-Słowik, Magdalena, Gołębiowska, Bożena, Sęk, Mateusz P., Nejbert, Krzysztof, Kotowski, Jakub, Marciniak-Maliszewska, Beata, Szuszkiewicz, Adam, et al. (2024) Heflikite, ideally Ca2(Al2Sc)(Si2O7)(SiO4)O(OH), the first scandium epidote-supergroup mineral from Jordanów Śląski, Lower Silesia, Poland and from Heftetjern, Tørdal, Norway. Mineralogical Magazine, 88 (3). 228-243 doi:10.1180/mgm.2023.98 **as Ce–La–Sc-enriched epidote-allanite minerals

ⓘ 'Epidote Supergroup'

Formula: (A1A2)(M1M2M3)O4[Si2O7][SiO4]O10

Description: At Heftetjern Ce–La–Sc-enriched epidote-allanite minerals of Epidote supergroups occurs. They appear as well-formed mm-sized plate-like, transparent crystals often forming aggregates, and in varying colours. Premlininary studies revealed that these are scandian or cerian epidotes. Later studies showed these to be chemically zoned with considerable variation in the different zones also in one single crystals. Zonated crystals with 8,3 wt% Sc2O3 has been found. The new mineral heflikite was defined from one such crystal. Since it is visually impossible to distinguish heflikite from the allanites or epidotes found at Heftetjernin the small vugs, the best way of labelling these without any analysis is Epidote Supergroup.

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ⓘ Euxenite-(Y)

Formula: (Y,Ca,Ce,U,Th)(Nb,Ta,Ti)2O6

Description: Originally descibed as "polycrase-(Y)", which was discredited as identical with euxenite-(Y) by IMA in

ⓘ Fluorite

Formula: CaF2

Description: yttrian variety (Raade & Kristiansen (2000)

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ⓘ 'Gadolinite Group'

Formula: A2M Q2Si2O8φ2

ⓘ Gadolinite-(Y)

Formula: Y2Fe2+Be2Si2O10

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ⓘ Gahnite

Formula: ZnAl2O4

Description: EDS-SEM identified

ⓘ Galena

Formula: PbS

ⓘ 'Garnet Group'

Formula: X3Z2(SiO4)3

ⓘ Heflikite (TL)

Formula: (CaCa)(AlAlSc)O[Si2O7][SiO4](OH)

Type Locality:

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ⓘ Heftetjernite (TL)

Formula: ScTaO4

Type Locality:

References:

Kolitsch, Uwe, Kristiansen, Roy, Raade, Gunnar, Tillmanns, Ekkehart (2010) Heftetjernite, a new scandium mineral from the Heftetjern pegmatite, Tordal, Norway. European Journal of Mineralogy, 22 (2) 309-316 doi:10.1127/0935-1221/2010/0022-1987

ⓘ Hellandite-(Y)

Formula: (Ca,REE)4Y2Al◻2(B4Si4O22) (OH)2

Habit: microcrystals

Colour: pale red

Description: in fluorite. A Mn-bearing (greater than 1 apfu) hellandite-(Y) occurs as pinkish yellow tiny granular crystals.

References:

Miyawaki, Ritsuro, Momma, Koichi, Yokoyama, Kazumi, Shigeoka, Masako, Matsubara, Satoshi, Ito, Miku, Nakai, Izumi, Kristiansen, Roy (2015) Mn-bearing hellandite-(Y) from Heftetjern pegmatite, Tørdal, Norway. The Canadian Mineralogist, 53 (2) 345-356 doi:10.3749/canmin.1400068

ⓘ Hellandite-(Y) var. Manganese-bearing Hellandite-(Y) (FRL)

Formula: Ca1.34Mn1.07Y2.75Yb0.38Al0.92Fe0.08Si4B4O21.21(OH)2.79

Type Locality:

Habit: granular crystals

Colour: Pinkish yellow

Description: Pinkish yellow granular crystals

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ⓘ Helvine

Formula: Be3Mn2+4(SiO4)3S

Habit: irregular masses several cm across; irregular grains

Colour: pinkish; deep brown-red

Description: Occurs as intimately intergrowth with light blue bazzite. Raade & Kristiansen 2000 found a scandian-rich helvite with up to 1,7 % Sc2O3

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ⓘ Hingganite-(Ce)

Formula: (Ce,REE)2(◻,Fe2+)Be2[SiO4]2(OH)2

Description: Small, white fanlike aggregates or massive aggregates < 1mm in diameter. Analysis showed it to be a Ca-bearing hellandite-(Ce) in intimately intergrowth with apatite

ⓘ Hingganite-(Y)

Formula: (Y,REE,Ca)2(◻,Fe2+)Be2[SiO4]2(OH)2

Habit: Aggregates of pseudohexagonal plates about 0,5 mm across; Blocky crystals to several mm; grains

Colour: Brownish, yellow and colorless

Description: Hingganite-(Y) occurs at Heftetjern with variable color, morphology and chemcical composition. A calcian hingganite-(Y) was described by Raade & Kristiansen 2000. It occurs as aggregates of yellowish, pseudohexagonal plates about 0,5 mm across. The structure of a triclinic Ca-B-Fe-rich hingganite-(Y) was analysed by Miyawaki et al. (2018), see also Kristiansen (2018)

References:

Raade, G., Ferraris, G., Gula, A., Ivaldi, G., Bernhard, F. (2002) Kristiansenite, a new calcium-scandium-tin sorosilicate from granite pegmatite in Tørdal, Telemark, Norway. Mineralogy and Petrology, 75 (1) 89-99 doi:10.1007/s007100200017

Miyawaki, R., Momma, K., Cooper, M.A., Hawthorne, F.C. & Kristiansen, R. (2018): Refinements of crystal structure of hingganite-(Y): Cation ordering and lowering symmetry. Abstracts, Annual meeting of REE society of Japan, March 2018.

ⓘ Ilmenite

Formula: Fe2+TiO3

ⓘ Ilmenite var. Manganese-bearing Ilmenite

Formula: (Fe,Mn)2+TiO3

ⓘ 'Ixiolite-(Mn2+)-Ixiolite-(Fe2+) Series'

Habit: The outline of the crystals being often rectangular or even square.

Description: up to 18,80 wt % Sc2O is reported. As up to 5mm large, black shiny cristals with a brownish tint.

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ⓘ 'Ixiolite-(Mn2+)-Ixiolite-(Fe2+) Series var. Scandian Ixiolite (of Bergstøl & Juve)'

Formula: ~(Sc,Ta,Nb,Sn,Fe,Ti)4O8

Description: up to 18,80 wt % Sc2O is reported. As up to 5mm large, black, shiny crystals with a weak brownish tint. Some crystals are partly altered to pyrochlore supergroup minerals.

ⓘ Kainosite-(Y)

Formula: Ca2(Y,Ce)2(Si4O12)(CO3) · H2O

Habit: square prismatic crystals to 2mm long

Colour: colourless

Description: found in fluorite

ⓘ Kamphaugite-(Y) ?

Formula: Ca(Y,REE)(CO3)2(OH) · H2O

Description: Doubt has been raised if the specimen analyzed and photograhed originates from the Heftetjern pegmatite, no similar specimen has been found at Heftetjern but at Skarsfjell or other localituies nearby ( R.Kristiansen & K.E.Larsen commentary 2009)

ⓘ Keiviite-(Y)

Formula: Y2Si2O7

✪ Kristiansenite (TL)

Formula: Ca4Sc2Sn2(Si2O7)2(Si2O6OH)2

Type Locality:

Habit: Triclinic

Colour: Colourless, greyish, yellowish

References:

Ferraris, G., Gula, A., Ivaldi, G., Nespolo, Massimo, Raade, G. (2001) Crystal structure of kristiansenite: a case of class IIB twinning by metric merohedry. Zeitschrift für Kristallographie - Crystalline Materials, 216 (8) doi:10.1524/zkri.216.8.442.20353

ⓘ 'Limonite'

ⓘ Magnetite

Formula: Fe2+Fe3+2O4

ⓘ Microcline

Formula: K(AlSi3O8)

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ⓘ Microcline var. Amazonite

Formula: K(AlSi3O8)

ⓘ 'Microlite Group'

Formula: A2-mTa2X6-wZ-n

Description: Bergstøl & Juve (1988) found a yttrian scandian microlite (uranian).

ⓘ 'Microlite Group var. Scandium Microlite (of Bergstøl & Juve)'

Description: Found in an altered area of an ixiolite.

ⓘ Milarite

Formula: K(◻H2O)Ca2(Be2Al)[Si12O30]

Description: Milarite of normal composition is rather common at Heftetjern, and it is visually not ditinguisable from oftedalite which is extremely rare and contains 5–7 wt% Sc2O3 and milarite with high yttrium content (rare). One sample with very high Y (~10 wt% Y2O3)was described as the new mineral Agakhanovite-(Y) by Hawthorne et al (2014).

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ⓘ Molybdenite

Formula: MoS2

ⓘ Monazite-(Ce)

Formula: Ce(PO4)

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ⓘ Muscovite

Formula: KAl2(AlSi3O10)(OH)2

ⓘ Nontronite

Formula: Na0.3Fe2((Si,Al)4O10)(OH)2 · nH2O

ⓘ Oftedalite (TL)

Formula: K◻2(ScCa)Be3[Si12O30]

Type Locality:

Habit: hexagonale prismatic xls showing {100} and {001}

Colour: greyish white

Description: Found in only one sample !

References:

Cooper, M. A., Hawthorne, F. C., Ball, N. A., Černý, Petr, Kristiansen, Roy (2006) Oftedalite, (ScCa)KBe3Si12O30, a new mineral species of the milarite group from the Heftetjern pegmatite, Tørdal, Norway: description and crystal structure. The Canadian Mineralogist, 44 (4) 943-949 doi:10.2113/gscanmin.44.4.943

ⓘ Opal

Formula: SiO2 · nH2O

ⓘ Phenakite

Formula: Be2SiO4

Description: Found on one specimen

ⓘ Plattnerite

Formula: PbO2

ⓘ 'Plumbomicrolite (of Hogarth 1977)'

Habit: octahedral crystals to 1 mm, often in aggregates.

Colour: greenish to brownish

Description: The mineral is typically zoned and has a heterogeneous composition within each zone.

ⓘ Pyrite

Formula: FeS2

ⓘ 'Pyrochlore Group'

Formula: A2Nb2(O,OH)6Z

Description: Pyrochlore Group minerals occurs at Heftetjern mostly as metamict alterations of ixiolite. Bergstøl & Juve (1988) found a scandian yttropyrochlore.

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ⓘ 'Pyrochlore Group var. Yttropyrochlore (of Hogarth 1977)'

Formula: A2Nb2(O,OH)6Z

Description: Bergstøl & Juve (1988) found a scandian yttropyrochlore. As altered metamict product after ixiolite

ⓘ Quartz

Formula: SiO2

Habit: massive

Description: partly smoky quartz

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ⓘ Quartz var. Smoky Quartz

Formula: SiO2

ⓘ ~~Rowlandite-(Y)~~

Formula: (Y,Ce)4Fe2+(Si2O7)2F2 (?)

Habit: Platy

Colour: Greenish-brown

Description: Showed to be a zonated mixture of gadolinite-(Y) and hingganite-(Y) with inclusions of a OH-gadolinite. (Kristiansen 2018)

ⓘ Rutile

Formula: TiO2

Description: scandian variety

ⓘ Rutile var. Ilmenorutile

Formula: (Ti,Nb)O2

Description: scandian variety

ⓘ Rynersonite

Formula: CaTa2O6

Habit: rectangular plates or as rulershaped striated crystals < 1mm

Colour: dull yellow to colorless

Description: as alteration product after (scandian )ixiolite or on the surface of porous cassiterite

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ⓘ Scandiobabingtonite

Formula: Ca2(Fe2+,Mn)ScSi5O14(OH)

Habit: fibrous and porous masses 2-3 mm across; blocky crystals

Colour: light green

Description: Intimate intergrowth with cascandite (Raade & Erambert (1999)

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ⓘ Schorl

Formula: NaFe2+3Al6(Si6O18)(BO3)3(OH)3(OH)

Colour: Greyishblue with a thin brownishrim

Description: A scandian schörl (Kristiansen 2018)

ⓘ Siderophyllite

Formula: KFe2+2Al(Al2Si2O10)(OH)2

Description: Wilhelmsen (2020) anlyses a sample of Lithian siderophyllite.

ⓘ 'Siderophyllite-Polylithionite Series'

Description: Dark mica, also described as'zinnwaldite' from Heftetjern.

ⓘ Spessartine

Formula: Mn2+3Al2(SiO4)3

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ⓘ Stilpnomelane

Formula: (K,Ca,Na)(Fe,Mg,Al)8(Si,Al)12(O,OH)36 · nH2O

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ⓘ Tantalite-(Fe)

Formula: Fe2+Ta2O6

Description: scandian variety

ⓘ Thorite

Formula: Th(SiO4)

Description: Found as a < 10 μm large crystal in quartz and as a inclusion in apatite (Laukert 2008) Found as inclusion in garnet (Steffensen 2018)

ⓘ Thorite var. Uranothorite

Formula: (Th,U)SiO4

ⓘ Thortveitite

Formula: Sc2Si2O7

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ⓘ Titanite

Formula: CaTi(SiO4)O

Description: occurs with different colours and crystal habits A stannian variety exist. The titanites from Heftetjern is quite variable in composition, and some Sc-rich, but often with high Ta and Sn.

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ⓘ Titanite var. Triclinic Titanite (FRL)

Type Locality:

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ⓘ 'Tourmaline'

Formula: A D3G6 (T6O18)(BO3)3X3Z

ⓘ Uedaite-(Ce)

Formula: (Mn2+Ce)(AlAlFe2+)O[Si2O7][SiO4](OH)

Habit: Not very well developed elongated, prismatic crystals

Colour: Black

Description: Analyzed and verified at Tokyo University.

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