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Franciscanite

A valid IMA mineral species

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Photos of Franciscanite (5)

Franciscanite Gallery Search Photos of Franciscanite

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Franciscanite

Pennsylvania Mine, Sugarloaf Mountain, Black Wonder Mining District, Santa Clara County, California, USA

Franciscanite

Gambatesa Mine, Reppia, Ne, Genoa, Liguria, Italy

Franciscanite

Gambatesa Mine, Reppia, Ne, Genoa, Liguria, Italy

Franciscanite

Pennsylvania Mine, Sugarloaf Mountain, Black Wonder Mining District, Santa Clara County, California, USA

Franciscanite

Gambatesa Mine, Reppia, Ne, Genoa, Liguria, Italy

Franciscanite

Gambatesa Mine, Reppia, Ne, Genoa, Liguria, Italy

Franciscanite

Pennsylvania Mine, Sugarloaf Mountain, Black Wonder Mining District, Santa Clara County, California, USA

Franciscanite

Gambatesa Mine, Reppia, Ne, Genoa, Liguria, Italy

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About FranciscaniteHide

Formula:

Mn²⁺₆(V⁵⁺,◻)₂(SiO₄)₂(O,OH)₆

Colour:

Brown red, red

Lustre:

Vitreous

Hardness:

Specific Gravity:

4.1

Crystal System:

Trigonal

Member of:

Welinite Group

Name:

Named after the Miocene age Franciscan Formation, where the mineral was found.

Type Locality:

ⓘ Pennsylvania Mine, Sugarloaf Mountain, Black Wonder Mining District, Santa Clara County, California, USA

This page provides mineralogical data about Franciscanite.

Unique IdentifiersHide

Mindat ID:

1590

Long-form identifier:

mindat:1:1:1590:1

GUID
(UUID V4):

d7aa4734-88f7-493b-894f-84bf474fd88d

IMA Classification of FranciscaniteHide

IMA status:

Approved

IMA Formula:

Mn²⁺₆(V⁵⁺◻)(SiO₄)₂O₃(OH)₃

Approval year:

1985

First published:

1986

Type description reference:

Dunn, Pete J., Peacor, Donald R., Erd, Richard C., Ramik, Robert A. (1986) Franciscanite and ürebroite, two new minerals from California and Sweden, related to redefined welinite. American Mineralogist, 71 (11-12) 1522-1526

Classification of FranciscaniteHide

Strunz-mindat (2024):

9.AF.75

9 : SILICATES (Germanates)
A : Nesosilicates
F : Nesosilicates with additional anions; cations in [4], [5] and/or only [6] coordination

Dana 8th ed.:

52.4.1.4

52 : NESOSILICATES Insular SiO₄ Groups and O,OH,F,H₂O
4 : Insular SiO₄ Groups and O, OH, F, and H₂O with cations in [6] and/or >[6] coordination

Hey's CIM Ref.:

17.7.2

17 : Silicates Containing other Anions
7 : Silicates with vanadate, arsenate or antimonate

Mineral SymbolsHide

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

Symbol	Source	Reference
Fcc	IMA–CNMNC	Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43

Physical Properties of FranciscaniteHide

Lustre:

Vitreous

Transparency:

Transparent

Colour:

Brown red, red

Comment:

Cherry-red when fresh, darkening with time.

Streak:

Brownish red

Hardness:

4 on Mohs scale

Cleavage:

None Observed

Fracture:

Irregular/Uneven

Density:

4.1(3) g/cm³ (Measured) 3.97 g/cm³ (Calculated)

Optical Data of FranciscaniteHide

Type:

Uniaxial (+)

RI values:

n_ω = 1.856(3) n_ε = 1.882 - 3.000

Max Birefringence:

δ = 0.026

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

Surface Relief:

Very High

Pleochroism:

Strong

Comments:

O = wine-red; E = dark red to nearly black

Comments:

Absorption is intense, E >> O.

Chemistry of FranciscaniteHide

Mindat Formula:

Mn²⁺₆(V⁵⁺,◻)₂(SiO₄)₂(O,OH)₆

Elements listed:

H, Mn, O, Si, V - search for minerals with similar chemistry

Crystallography of FranciscaniteHide

Crystal System:

Trigonal

Class (H-M):

3 - Pyramidal

Space Group:

Cell Parameters:

a = 8.1518(3) Å, c = 4.8091(2) Å

Ratio:

a:c = 1 : 0.59

Unit Cell V:

276.76 Å³ (Calculated from Unit Cell)

Crystal StructureHide

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Data courtesy of the American Mineralogist Crystal Structure Database. Click on an AMCSD ID to view structure

ID	Species	Reference	Link	Year	Locality	Pressure (GPa)	Temp (K)
0014805	Franciscanite	Pertlik F (1986) The crystal structure of franciscanite, Mn3(Vx_1-x)(SiO4)(O,OH)3,(x ~ 0.5) California, USA Neues Jahrbuch fur Mineralogie, Monatshefte 1986 493-499		1986	Franciscan Complex, Pennsylvania mine, Santa Clara County,	0	293

CIF Raw Data - click here to close

data_global
_chemical_name_mineral 'Franciscanite'
loop_
_publ_author_name
'Pertlik F'
_journal_name_full 'Neues Jahrbuch fur Mineralogie, Monatshefte'
_journal_volume 1986 
_journal_year 1986
_journal_page_first 493
_journal_page_last 499
_publ_section_title
;
 The crystal structure of franciscanite, Mn3(Vx_1-x)(SiO4)(O,OH)3,(x ~ 0.5)
 California, USA
;
_database_code_amcsd 0014805
_chemical_compound_source 'Franciscan Complex, Pennsylvania mine, Santa Clara County,'
_chemical_formula_sum 'Mn3 V.5 Si O7 H3'
_cell_length_a 8.1518
_cell_length_b 8.1518
_cell_length_c 4.8091
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 120
_cell_volume 276.759
_exptl_crystal_density_diffrn      4.001
_symmetry_space_group_name_H-M 'P 3'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '-y,x-y,z'
  '-x+y,-x,z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
Mn1   0.58480   0.89160   0.00000   1.00000
Mn2   0.40900   0.11510   0.49940   1.00000
V1   0.00000   0.00000   0.96090   0.64000
V2   0.00000   0.00000   0.43240   0.36000
Si1   0.33333   0.66667   0.43420   1.00000
Si2   0.66667   0.33333   0.93980   1.00000
O2   0.36660   0.86770   0.29450   1.00000
O22   0.62770   0.13170   0.79730   1.00000
O3   0.33333   0.66667   0.78440   1.00000
O33   0.66667   0.33333   0.26700   1.00000
O-H1   0.78890   0.83580   0.78140   1.00000
O-H11   0.21350   0.16300   0.26470   1.00000
loop_
_atom_site_aniso_label
_atom_site_aniso_U_11
_atom_site_aniso_U_22
_atom_site_aniso_U_33
_atom_site_aniso_U_12
_atom_site_aniso_U_13
_atom_site_aniso_U_23
Mn1 0.01100 0.00500 0.01500 0.00000 -0.00100 -0.00100
Mn2 0.00900 0.01700 0.00900 0.00500 -0.00100 -0.00200
V1 0.00100 0.00100 0.03100 0.00000 0.00000 0.00000
V2 0.03500 0.03500 0.00100 0.01700 0.00000 0.00000
Si1 0.01500 0.01500 0.00700 0.00700 0.00000 0.00000
Si2 0.00600 0.00600 0.01000 0.00300 0.00000 0.00000
O2 0.00800 0.01200 0.01600 0.00000 0.00700 0.00200
O22 0.02200 0.00900 0.00900 0.00900 0.00600 0.00200
O3 0.01200 0.01200 0.03600 0.00600 0.00000 0.00000
O33 0.00100 0.00100 0.01500 0.00000 0.00000 0.00000
O-H1 0.02900 0.01300 0.02300 0.01300 -0.01300 -0.00900
O-H11 0.00300 0.02000 0.01100 0.00400 -0.00700 -0.00100

X-Ray Powder DiffractionHide

Powder Diffraction Data:

d-spacing	Intensity
2.331 Å	(100)
3.105 Å	(90)
2.844 Å	(90)
1.785 Å	(70)
1.538 Å	(50)
2.668 Å	(40)
3.97 Å	(30)

Geological EnvironmentHide

Paragenetic Mode(s):

Paragenetic Mode	Earliest Age (Ga)
High-𝑇 alteration and/or metamorphism
32 : Ba/Mn/Pb/Zn deposits, including metamorphic deposits

Type Occurrence of FranciscaniteHide

Type Locality:

ⓘ Pennsylvania Mine, Sugarloaf Mountain, Black Wonder Mining District, Santa Clara County, California, USA

General Appearance of Type Material:

Glassy, irregular grains, up to 1.0 mm in diameter.

Place of Conservation of Type Material:

National Museum of Natural History, Washington, D.C., USA, 163041.

Geological Setting of Type Material:

Segregations in a sheared sonolite-hausmannite-gageite assemblage in chert.

Associated Minerals at Type Locality:

Reference:

Pete J. Dunn, Donald R. Peacor, Richard C. Erd, and Robert A. Ramik (1986) Franciscanite and örebroite, two new minerals from California and Sweden, related to redefined welinite. American Mineralogist, 71, 1522-1526.

Synonyms of FranciscaniteHide

IMA1985-038

Other Language Names for FranciscaniteHide

German:Franciscanit

Russian:Францисканит

Spanish:Franciscanita

Relationship of Franciscanite to other SpeciesHide

Member of:

Welinite Group

Other Members of this group:

Barwoodite	Mn²⁺₆Nb⁵⁺(SiO₄)₂O₃(OH)₃	Trig. 3 : P3
Örebroite	Mn²⁺₃(Sb⁵⁺,Fe³⁺)(SiO₄)(O,OH)₃	Trig. 3 : P3
Scorticoite	Mn₆(Sb,◻)_Σ2(SiO₄)₂O₃(OH)₃	Trig. 3 : P3
Welinite	Mn²⁺₆(W⁶⁺,Mg)₂(SiO₄)₂(O,OH)₆	Trig. 3 : P3

Related Minerals - Strunz-mindat Grouping Hide

9.AF.	Chegemite	Ca₇(SiO₄)₃(OH)₂	Orth. mmm (2/m 2/m 2/m)
9.AF.	Barwoodite	Mn²⁺₆Nb⁵⁺(SiO₄)₂O₃(OH)₃	Trig. 3 : P3
9.AF.	Jingwenite-(Y)	YAlV⁴⁺(SiO₄)O₂(OH)₂	Mon. 2/m
9.AF.05	Sillimanite	Al₂(SiO₄)O	Orth. mmm (2/m 2/m 2/m)
9.AF.05	Xenolite	Al₁₀Si₈O₃₁
9.AF.10	Andalusite	Al₂(SiO₄)O	Orth. mmm (2/m 2/m 2/m) : Pnnm
9.AF.10	Kanonaite	Mn³⁺Al(SiO₄)O	Orth. mmm (2/m 2/m 2/m) : Pnnm
9.AF.15	Kyanite	Al₂(SiO₄)O	Tric. 1 : P1
9.AF.20	Mullite	Al_4+2xSi_2-2xO_10-x	Orth. mmm (2/m 2/m 2/m) : Pbam
9.AF.20	Krieselite	Al₂(GeO₄)F₂	Orth. mmm (2/m 2/m 2/m) : Pnma
9.AF.23	Boromullite	Al₉BSi₂O₁₉	Orth. mm2 : Cmc2₁
9.AF.25	Yoderite	Mg(Al,Fe³⁺)₃(SiO₄)₂O(OH)	Mon. 2/m : P2₁/m
9.AF.30	Magnesiostaurolite	Mg(Mg,Li)₃(Al,Mg)₁₈Si₈O₄₄(OH)₄	Mon. 2/m : B2/m
9.AF.30	Staurolite	Fe²⁺₂Al₉Si₄O₂₃(OH)	Mon. 2/m : B2/m
9.AF.30	Zincostaurolite	Zn₂Al₉Si₄O₂₃(OH)	Mon. 2/m : B2/m
9.AF.35	Topaz	Al₂(SiO₄)(F,OH)₂	Orth. mmm (2/m 2/m 2/m)
9.AF.40	Norbergite	Mg₃(SiO₄)F₂	Orth. mmm (2/m 2/m 2/m)
9.AF.45	Alleghanyite	Mn²⁺₅(SiO₄)₂(OH)₂	Mon. 2/m : P2₁/b
9.AF.45	Chondrodite	Mg₅(SiO₄)₂F₂	Mon. 2/m : P2₁/b
9.AF.45	Reinhardbraunsite	Ca₅(SiO₄)₂(OH,F)₂	Mon. 2/m : P2₁/b
9.AF.45	Kumtyubeite	Ca₅(SiO₄)₂F₂	Mon. 2/m : P2₁/b
9.AF.45	Hydroxylchondrodite	Mg₅(SiO₄)₂(OH)₂	Mon. 2/m : P2₁/b
9.AF.50	Humite	Mg₇(SiO₄)₃F₂	Orth. mmm (2/m 2/m 2/m) : Pnma
9.AF.50	Manganhumite	(Mn²⁺,Mg)₇(SiO₄)₃(OH)₂	Orth. mmm (2/m 2/m 2/m)
9.AF.50	Unnamed (Ca-analogue of Humite)	Ca₇(SiO₄)₄F₂	Orth. mmm (2/m 2/m 2/m)
9.AF.50	Fluorchegemite	Ca₇(SiO₄)₃F₂	Orth. mmm (2/m 2/m 2/m)
9.AF.50	Unnamed (OH-analogue of humite)	Mg₇(SiO₄)₃(OH)₂	Orth.
9.AF.55	Clinohumite	Mg₉(SiO₄)₄F₂	Mon. 2/m : P2₁/b
9.AF.55	Sonolite	Mn²⁺₉(SiO₄)₄(OH)₂	Mon. 2/m : P2₁/b
9.AF.55	Hydroxylclinohumite	Mg₉(SiO₄)₄(OH)₂	Mon. 2/m : P2₁/b
9.AF.60	Leucophoenicite	Mn²⁺₇(SiO₄)₃(OH)₂	Mon. 2/m : P2₁/b
9.AF.65	Ribbeite	Mn²⁺₅(SiO₄)₂(OH)₂	Orth. mmm (2/m 2/m 2/m)
9.AF.70	Jerrygibbsite	Mn²⁺₉(SiO₄)₄(OH)₂	Orth. mmm (2/m 2/m 2/m) : Pbcn
9.AF.75	Örebroite	Mn²⁺₃(Sb⁵⁺,Fe³⁺)(SiO₄)(O,OH)₃	Trig. 3 : P3
9.AF.75	Welinite	Mn²⁺₆(W⁶⁺,Mg)₂(SiO₄)₂(O,OH)₆	Trig. 3 : P3
9.AF.75	Scorticoite	Mn₆(Sb,◻)_Σ2(SiO₄)₂O₃(OH)₃	Trig. 3 : P3
9.AF.80	Ellenbergerite	Mg₆(Mg,Ti,Zr,◻)₂(Al,Mg)₆Si₈O₂₈(OH)₁₀	Hex. 6 : P6₃
9.AF.85	Chloritoid	(Fe²⁺,Mg,Mn²⁺)Al₂(SiO₄)O(OH)₂	Mon. 2/m : B2/b
9.AF.85	Magnesiochloritoid	MgAl₂(SiO₄)O(OH)₂	Mon. 2/m : B2/b
9.AF.85	Ottrélite	(Mn²⁺,Fe²⁺,Mg)Al₂(SiO₄)O(OH)₂	Mon.
9.AF.90	Poldervaartite	CaCa[SiO₃(OH)](OH)	Orth. mmm (2/m 2/m 2/m) : Pbca
9.AF.90	Olmiite	CaMn²⁺[SiO₃(OH)](OH)	Orth. mmm (2/m 2/m 2/m) : Pbca
9.AF.95	Pilawite-(Y)	Ca₂Y₂Al₄(SiO₄)₄O₂(OH)₂	Mon. 2/m : P2₁/b

Other InformationHide

Notes:

May be weakly magnetic, possibly resulting from tiny opaque inclusions.

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 FranciscaniteHide

mindat.org URL:

https://www.mindat.org/min-1590.html
Please feel free to link to this page.

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External Links:

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Raman and XRD data at RRUFF project

References and PDF downloads at RRUFF project

American Mineralogist Crystal Structure Database

Handbook of Mineralogy page PDF

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References for FranciscaniteHide

Reference List:

Pertlik, F. (1986) The crystal structure of franciscanite, Mn₃(V_x◻_1-x)(SiO₄)(O,OH)₃, [x ~ 0.5]. Neues Jahrbuch für Mineralogie - Monatshefte, 1986. 493-499

(2023) Franciscanite. Handbook of Mineralogy. Mineralogical Society of America

Localities for FranciscaniteHide

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

- 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.


Italy
Liguria Genoa Ne Reppia ⓘ Gambatesa Mine	Balestra et al. (2009)

Japan
Saitama Prefecture Hanno City ⓘ Komatsu mine	Yamada et al (2000)

USA (TL)
California Santa Clara County Black Wonder Mining District Sugarloaf Mountain ⓘ Pennsylvania Mine (TL)	www.mineralsocal.org +1 other reference

Franciscanite

About FranciscaniteHide

Unique IdentifiersHide

IMA Classification of FranciscaniteHide

Classification of FranciscaniteHide

Mineral SymbolsHide

Physical Properties of FranciscaniteHide

Optical Data of FranciscaniteHide

Chemistry of FranciscaniteHide

Crystallography of FranciscaniteHide

Crystal StructureHide

X-Ray Powder DiffractionHide

Geological EnvironmentHide

Type Occurrence of FranciscaniteHide

Synonyms of FranciscaniteHide

Other Language Names for FranciscaniteHide

Relationship of Franciscanite to other SpeciesHide

Related Minerals - Strunz-mindat GroupingHide

Other InformationHide

Internet Links for FranciscaniteHide

References for FranciscaniteHide

Localities for FranciscaniteHide

Locality ListHide

Related Minerals - Strunz-mindat Grouping Hide