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Tvedalite

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Big Photo

Saga Pearl quarry, Tvedalen, Larvik, Vestfold, Norway
© OT. Ljostad

Show Tvedalite Photos (6)



Formula:
(Ca,Mn)
 
4
Be
 
3
Si
 
6
O
 
17
(OH)
 
4
 · 3H
 
2
O
System:OrthorhombicColour:Creamy-white, light beige
Hardness:4½
Name:Named after its discovery locality, Vevja quarry, Tvedalen area, Vestfold, Norway.


May belong to the Zeolite Group (uncertain since crystal structure has not been determined yet).

Classification of Tvedalite

IMA status:Approved
Strunz 8th edition ID:8/G.07-25
Nickel-Strunz 10th (pending) edition ID:9.DF.20

9 : SILICATES (Germanates)
D : Inosilicates
F : Inosilicates with 2-periodic multiple chains
Dana 8th edition ID:70.5.2.1

70 : INOSILICATES Column or Tube Structures
5 : Column or Tube Structures with chains linked by Be
Hey's CIM Ref.:14.3.19

14 : Silicates not Containing Aluminum
3 : Silicates of Be
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Type Occurrence of Tvedalite

Type Locality:Vevja quarry, Tvedalen, Larvik, Vestfold, Norway
General Appearance of Type Material:Spherulites up to 3 mm in diameter composed of densely packed, radially oriented platelets (a few μ in length). The spherulites are overgrown by a crust of chiavennite.
Year of Discovery:1992
Geological Setting of type material:In heavily zeolitized and hydrothermally parts of irregular nepheline syenite pegmatites

Physical Properties of Tvedalite

Lustre:Vitreous
Diaphaneity (Transparency):Translucent
Colour:Creamy-white, light beige
Streak:white
Hardness (Mohs):4½
Hardness Data:Estimated
Cleavage:Perfect
{010}
Density (measured):2.541 g/cm3
Density (calculated):2.554 g/cm3

Crystallography of Tvedalite

Crystal System:Orthorhombic
Cell Parameters:a = 8.72Å, b = 23.14Å, c = 4.92Å
Ratio:a:b:c = 0.377 : 1 : 0.213
Unit Cell Volume:V 992.76 ų (Calculated from Unit Cell)
X-Ray Powder Diffraction:
d-spacingIntensity
11.6 (93)
5.80 (68)
3.87 (75)
3.16 (74)
2.889 (75)
2.837 (100)
2.494 (58)

Optical Data of Tvedalite

Type:Biaxial
Dispersion:r > v

Chemical Properties of Tvedalite

Formula:
(Ca,Mn)
 
4
Be
 
3
Si
 
6
O
 
17
(OH)
 
4
 · 3H
 
2
O
Essential elements:Be, Ca, H, O, Si
All elements listed in formula:Be, Ca, H, Mn, O, Si
Common Impurities:Al,Fe

Relationship of Tvedalite to other Species

Related Minerals - Nickel-Strunz Grouping):

- +
9.DF.05Chesterite
(Mg,Fe)
 
17
Si
 
20
O
 
54
(OH)
 
6
9.DF.05Clinojimthompsonite
(Mg,Fe)
 
5
Si
 
6
O
 
16
(OH)
 
2
9.DF.05Jimthompsonite
(Mg,Fe)
 
5
Si
 
6
O
 
16
(OH)
 
2
9.DF.15Ershovite
Na
 
4
K
 
3
(Fe,Mn,Ti)
 
2
Si
 
8
O
 
22
(OH)
 
4
 · 4H
 
2
O
9.DF.15Paraershovite
Na
 
3
K
 
3
Fe
3+
2
Si
 
8
O
 
20
(OH)
 
4
 · 4H
 
2
O
9.DF.25Bavenite
Ca
 
4
Be
 
2
Al
 
2
Si
 
9
O
 
26
(OH)
 
2
9.DF.30Bigcreekite
BaSi
 
2
O
 
5
 · 4H
 
2
O
Related Minerals - Hey's Index Grouping:

- +
14.3.1Phenakite
Be
 
2
SiO
 
4
14.3.2Bertrandite
Be
 
4
(Si
 
2
O
 
7
)(OH)
 
2
14.3.3Beryllite
Be
 
3
(SiO
 
4
)(OH)
 
2
 · H
 
2
O
14.3.4Liberite
Li
 
2
BeSiO
 
4
14.3.5Chkalovite
Na
 
2
BeSi
 
2
O
 
6
14.3.6Eudidymite
Na
 
2
Be
 
2
Si
 
6
O
 
15
 · H
 
2
O
14.3.7Epididymite
Na
 
2
Be
 
2
Si
 
6
O
 
15
 · H
 
2
O
14.3.8Gugiaite
Ca
 
2
Be(Si
 
2
O
 
7
)
14.3.9Jeffreyite
(Ca,Na)
 
2
(Be,Al)(Si
 
2
O
 
7
,HSi
 
2
O
 
7
)
14.3.10Semenovite-(Ce)
Na
 
8
Ca
 
2
FeBe
 
6
Ce
 
2
Si
 
14
O
 
40
(OH)
 
4
F
 
4
14.3.11Barylite
Be
 
2
Ba(Si
 
2
O
 
7
)
14.3.12Hingganite-(Ce)
(Ce,REE)
 
2
(□,Fe
2+
 
)Be
 
2
[SiO
 
4
]
 
2
(OH)
 
2
14.3.13Hingganite-(Yb)
(Yb,Y,REE)
 
2
□Be
 
2
[SiO
 
4
]
 
2
(OH)
 
2
14.3.14Hingganite-(Y)
(Y,REE,Ca)
 
2
(□,Fe
2+
 
)Be
 
2
[SiO
 
4
]
 
2
(OH)
 
2
14.3.15Minasgeraisite-(Y)
CaBe
 
2
Y
 
2
Si
 
2
O
 
10
14.3.16Sørensenite
Na
 
4
SnBe
 
2
Si
 
6
O
 
16
(OH)
 
4
14.3.17Trimerite
CaMn
2+
2
Be
 
3
(SiO
 
4
)
 
3
14.3.18Chiavennite
CaMnBe
 
2
Si
 
5
O
 
13
(OH)
 
2
 · 2H
 
2
O
14.3.20Harstigite
Ca
 
6
(Mn,Mg)Be
 
4
Si
 
6
(O,OH)
 
24
14.3.21Sverigeite
NaMnMgSnBe
 
2
(SiO
 
4
)
 
3
(OH)
14.3.22Joesmithite
{Pb}{Ca
 
2
}{Mg
 
3
Fe
3+
2
}(Be
 
2
Si
 
6
O
 
22
)(OH)
 
2
14.3.23Gadolinite-(Y)
Y
 
2
Fe
2+
 
Be
 
2
Si
 
2
O
 
10
14.3.24Gadolinite-(Ce)
(Ce,La,Nd,Y)
 
2
Fe
2+
 
Be
 
2
Si
 
2
O
 
10
14.3.25Calciogadolinite-(Y)
(YCa)
 
2
Fe
3+
 
Be
 
2
[SiO
 
4
]
 
2
O
 
2

Other Names for Tvedalite

Synonyms:
IMA1990-027
Other Languages:
German:Tvedalit
Spanish:Tvedalita

Other Information

Fluorescence in UV light:non-fluorescent
Health Warning:No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.

References for Tvedalite

Reference List:

- +
Larsen, A. O., Åsheim, A., Raade, G. & Taftø, J. (1992): Tvedalite, (Ca,Mn)4Be3Si6O17(OH)4•H2O, a new mineral from syenite pegmatite in the Oslo Region, Norway. American Mineralogist: 77: 438-443.

New Minerals (1997), New Minerals 1990-1994.

Internet Links for Tvedalite

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    • Localities for Tvedalite

    Hide Locality List
    (TL) indicates type locality. ? indicates mineral may be doubtful at this locality. All other localities listed without reference should be considered as uncertain and unproven until references can be found.
    Norway
     
    • Telemark
      • Porsgrunn
        • Mørje
          • Sagåsen (Strandåsen)
    		Larsen, A.O., Åsheim, A. and Gault, R. A. (2005): Minerals of the eudialyte group from the Sagåsen larvikite quarry, Porsgrunn, Norway. Norsk Bergverksmuseum Skrifter 30: 58-62
    • Vestfold
      • Larvik
        • Tvedalen
    		Nordrum, F.S. (2002): Nyfunn av mineraler i Norge 2001-2002. STEIN 29 (2): 4-10; Larsen, A. O. (ed.) (2010): The Langesundsfjord. History, geology, pegmatites, minerals. Bode Verlag Gmbh, Salzhemmendorf, Germany, 240 pp
    Nordrum, F. S. (2004): Nyfunn av mineraler i Norge 2003-2004. STEIN 31 (2), 36-44; Larsen, A. O. (ed.) (2010): The Langesundsfjord. History, geology, pegmatites, minerals. Bode Verlag Gmbh, Salzhemmendorf, Germany, 240 pp
    Larsen, A. O.; Åsheim, A.; Raade, G. & Taftø, J. (1992): Tvedalite, (Ca,Mn)4Be3Si6O17(OH)4• 3H2O, a new mineral from syenite pegmatite in the Oslo Region, Norway, American Mineralogist 77, 438-443
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