Julgoldite-(Fe2+) (original) (raw)

A valid IMA mineral species

About Julgoldite-(Fe2+)Hide

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Formula:

Ca2Fe2+Fe3+2[Si2O6OH][SiO4](OH)2(OH)

Colour:

Deep black, greenish black to green in small fragments

Specific Gravity:

3.58 - 3.60

Crystal System:

Monoclinic

Name:

Named for its relationship to julgoldite-(Fe3+).

Julian Royce Goldsmith (26 February 1918, Chicago, Illinois, USA - 23 January 1999, USA), geochemist at the University of Chicago. He was an expert on feldspars and carbonates. He also served as president of the Geochemical Society, the Mineralogical Soeciety of America, and the Geological Society of America.

Unique IdentifiersHide

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Long-form identifier:

mindat:1:1:2120:9

2c52adce-a588-4a83-9e50-525b178e851c

IMA Classification of Julgoldite-(Fe2+)Hide

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IMA Formula:

Ca2Fe2+Fe3+2(Si2O7)(SiO4)(OH)2 · H2O

Classification of Julgoldite-(Fe2+)Hide

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9.BG.20

9 : SILICATES (Germanates)
B : Sorosilicates
G : Sorosilicates with mixed SiO4 and Si2O7 groups; cations in octahedral [6] and greater coordination

58.2.2.1

58 : SOROSILICATES Insular, Mixed, Single, and Larger Tetrahedral Groups
2 : Insular, Mixed, Single, and Larger Tetrahedral Groups with cations in [6] and higher coordination; single and double groups (n = 1, 2)

14.22.8

14 : Silicates not Containing Aluminum
22 : Silicates of Fe and Ca

Mineral SymbolsHide

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As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.

Please only use the official IMA–CNMNC symbol. Older variants are listed for historical use only.

Physical Properties of Julgoldite-(Fe2+)Hide

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Colour:

Deep black, greenish black to green in small fragments

Streak:

Greenish olive with a bluish tinge

Cleavage:

Perfect
{100} and {001}

Density:

3.58 - 3.60 g/cm3 (Measured) 3.56 g/cm3 (Calculated)

Optical Data of Julgoldite-(Fe2+)Hide

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RI values:

_n_α = 1.776(4) _n_β = 1.814(4) _n_γ = 1.836(4)

2V:

Measured: 50° to 70°, Calculated: 73°

δ = 0.060

Image shows birefringence interference colour range (at 30µm thickness)
and does not take into account mineral colouration.

Comments:

X = pale brown; Y = pale brownish green; Z = deep emerald-green.

Chemistry of Julgoldite-(Fe2+)Hide

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Mindat Formula:

Ca2Fe2+Fe3+2[Si2O6OH][SiO4](OH)2(OH)

Crystallography of Julgoldite-(Fe2+)Hide

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Crystal System:

Monoclinic

Class (H-M):

2/m - Prismatic

Cell Parameters:

a = 8.922(4) Å, b = 6.081(3) Å, c = 19.432(9) Å
β = 97.60(6)°

Ratio:

a:b:c = 1.467 : 1 : 3.196

Unit Cell V:

1,045.02 ų (Calculated from Unit Cell)

Morphology:

fan-shaped, plumose crystal groups; granular.

Twinning:

Twin plane {001}, typically repeated, common.

Comment:

Space Group: A2/m:

X-Ray Powder DiffractionHide

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Powder Diffraction Data:

Geological EnvironmentHide

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Type Occurrence of Julgoldite-(Fe2+)Hide

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Place of Conservation of Type Material:

Swedish Museum of Natural History, Stockholm, Sweden; Harvard University, Cambridge, Massachusetts, 109641, 109642; National Museum of Natural History, Washington, D.C., USA, 137014.

Geological Setting of Type Material:

Associated Minerals at Type Locality:

Other Language Names for Julgoldite-(Fe2+)Hide

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Relationship of Julgoldite-(Fe2+) to other SpeciesHide

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Other Members of this group:

Common AssociatesHide

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Associated Minerals Based on Photo Data:

Related Minerals - Strunz-mindat GroupingHide

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Other InformationHide

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Health Risks:

No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.

Internet Links for Julgoldite-(Fe2+)Hide

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References for Julgoldite-(Fe2+)Hide

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Localities for Julgoldite-(Fe2+)Hide

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This map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the symbol to view information about a locality. The symbol next to localities in the list can be used to jump to that position on the map.

Locality ListHide

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- This locality has map coordinates listed. - This locality has estimated coordinates. ⓘ - Click for references and further information on this occurrence. ? - Indicates mineral may be doubtful at this locality. - Good crystals or important locality for species. - World class for species or very significant. (TL) - Type Locality for a valid mineral species. (FRL) - First Recorded Locality for everything else (eg varieties). Struck out - Mineral was erroneously reported from this locality. Faded * - Never found at this locality but inferred to have existed at some point in the past (e.g. from pseudomorphs).

All localities listed without proper references should be considered as questionable.

Germany
Baden-Württemberg Freiburg Region Lörrach Malsburg-Marzell ⓘ Malsburg	70. +1 other reference
Ortenaukreis Haslach im Kinzigtal Haslach im Kinzigtal ⓘ Amphibolite quarry (Vulkan quarry)	Walenta (1992)
Rhineland-Palatinate Donnersbergkreis Nordpfälzer Land Waldgrehweiler ⓘ Wolfsmühle Quarry	Poser et al. (2004)
Kaiserslautern Otterbach-Otterberg Niederkirchen ⓘ Rauschermühle Quarry	Weiß (1990)
Kusel Lauterecken-Wolfstein Kreimbach-Kaulbach ⓘ Andesite quarry	Weiß (1990)
Saxony Mittelsachsen Bobritzsch-Hilbersdorf ⓘ Naundorf quarry (Buchberg quarry)	Grütze (2006)
India
Maharashtra Konkan Division Salsette Island Mumbai Suburban District Malad ⓘ Malad Quarry	Wise and Moller (1990)
Nashik Division ⓘ Jalgaon District	Fabre Minerals
Italy
Sardinia Sassari Province La Maddalena La Maddalena Island ⓘ Cala Francese Quarries	Gamboni (2003)
Japan
Shimane Prefecture Matsue City Kitaura ⓘ Kouragahana	Matsubara et al (1992)
Norway
Møre og Romsdal Fjord Norddal Tafjord ⓘ FV 92 Roadcut Muldal	Brastad (1982) +1 other reference
Sweden (TL)
Värmland County Filipstad Långban Ore District ⓘ Långban Mine (TL)	Moore (1967) +2 other references
ⓘ Amerika stope	Moore (1967) +2 other references
Persberg ore district Pajsberg ⓘ Harstigen Mine	Nysten (1984) +1 other reference
Ukraine
Crimea Bakhchysarai Trudolyubovka ⓘ Pervomaiskii quarry	Karpenko V. (New Data on Minerals) +1 other reference
USA
California Trinity County Coastal Range Mad River Rock ⓘ Hale Creek Mine	Van Nostrand Reinholt Press: 493 +2 other references
Connecticut Litchfield County Woodbury Orenaug Hills ⓘ O & G Southbury Quarry (Silliman Quarry; O & G No. 2 Quarry)	Martins da Pedra specimen +1 other reference