Forêtite
A valid IMA mineral species
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About Forêtite
Jean-Paul Forêt & Valérie Galéa-Clolus
Cap Garonne Mine, Le Pradet, Toulon, Var, Provence-Alpes-Côte d'Azur, France
Cap Garonne Mine, Le Pradet, Toulon, Var, Provence-Alpes-Côte d'Azur, France
Formula:
Cu2Al2(AsO4)(OH,O,H2O)6
Colour:
Pale blue
Lustre:
Vitreous
Hardness:
3 - 4
Specific Gravity:
3.286 (Calculated)
Crystal System:
Triclinic
Name:
The mineral is named in honour of Dr Jean-Paul Forêt (b. 1943), retired engineer of the French Ministry of Equipment, who worked as geologist-in-charge of major risks and the environment. He was a co-founder of the project which turned the Cap Garonne mine into a nationally protected site and museum in 1994 (Musée de la Mine de Cap Garonne), and has acted as a scientific advisor to the museum from then until now.
Pale blue microcrystalline mineral forming tiny globules and thin crusts.
Originally described as an "Unnamed (Cu-Al Arsenate)" (Chiappero, 1993), then approved in 2012 using new material (Mills et al., 2012).
Visually similar to pale blue (Cu-bearing) crandallite-group minerals.
Originally described as an "Unnamed (Cu-Al Arsenate)" (Chiappero, 1993), then approved in 2012 using new material (Mills et al., 2012).
Visually similar to pale blue (Cu-bearing) crandallite-group minerals.
Name Encoding
ASCII-7:
Foretite
Unique Identifiers
Mindat ID:
42728
Long-form identifier:
mindat:1:1:42728:5
Similar Names
| Ferutite | A synonym of 'Davidite' | |
| Foordite | A valid IMA mineral species | Sn2+Nb2O6 |
| Fordite | An artificial material | |
| Freedite | A valid IMA mineral species | Cu+Pb8(AsO3)2O3Cl5 |
IMA Classification of Forêtite
Approved
IMA Formula:
Cu2+2Al2(As5+O4)(OH,O,H2O)6
Approval year:
2012
First published:
2012
Classification of Forêtite
8.DF.50
8 : PHOSPHATES, ARSENATES, VANADATES
D : Phosphates, etc. with additional anions, with H2O
F : With only medium-sized cations, (OH,etc.):RO4 > 3:1
8 : PHOSPHATES, ARSENATES, VANADATES
D : Phosphates, etc. with additional anions, with H2O
F : With only medium-sized cations, (OH,etc.):RO4 > 3:1
Mineral Symbols
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
| Symbol | Source | Reference for Standard |
|---|---|---|
| Frê | 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 Forêtite
Vitreous
Transparency:
Transparent, Translucent
Colour:
Pale blue
Streak:
Very pale blue
Hardness:
3 - 4 on Mohs scale
Hardness Data:
Estimated
Tenacity:
Brittle
Cleavage:
Poor/Indistinct
Parallel to the flattening of the platelets
Parallel to the flattening of the platelets
Density:
3.286 g/cm3 (Calculated)
Optical Data of Forêtite
Type:
Biaxial
Pleochroism:
Non-pleochroic
Chemistry of Forêtite
Mindat Formula:
Cu2Al2(AsO4)(OH,O,H2O)6
Element Weights:
Crystallography of Forêtite
Crystal System:
Triclinic
Class (H-M):
1 - Pinacoidal
Space Group:
P1
Setting:
P1
Cell Parameters:
a = 6.969(9) Å, b = 7.676(9) Å, c = 8.591(11) Å
α = 82.01(9)°, β = 71.68(8)°, γ = 102.68(8)°
α = 82.01(9)°, β = 71.68(8)°, γ = 102.68(8)°
Ratio:
a:b:c = 0.908 : 1 : 1.119
Unit Cell V:
414.76 ų (Calculated from Unit Cell)
Comment:
New structure type
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 7.307 Å | (100) |
| 4.519 Å | (23) |
| 4.277 Å | (18) |
| 3.455 Å | (17) |
| 3.141 Å | (24) |
| 2.818 Å | (24) |
| 2.719 Å | (20) |
| 2.343 Å | (22) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 7: Great Oxidation Event | <2.4 |
| 47a : [Near-surface hydration of prior minerals] | |
| 47d : [Arsenates, antimonates, selenates, bismuthinates] |
Type Occurrence of Forêtite
General Appearance of Type Material:
Pale blue aggregates, up to about 0.1 mm across, which consist of minute plates, each no more than 20 µm in length.
Place of Conservation of Type Material:
Natural History Museum of Los Angeles County, Los Angeles, USA, catalogue numbers 63573, 63574, 63575, 63576 and 63577.
Museum Victoria, Melbourne, Australia, registration number M51746.
Muséum National d’Histoire Naturelle, Paris, France, catalogue 211.5.
Museum Victoria, Melbourne, Australia, registration number M51746.
Muséum National d’Histoire Naturelle, Paris, France, catalogue 211.5.
Associated Minerals at Type Locality:
Synonyms of Forêtite
Other Language Names for Forêtite
Common Associates
Associations Based on Photo Data:
| 9 photos of Forêtite associated with 'Mansfieldite-Scorodite Series' | |
| 3 photos of Forêtite associated with Parnauite | Cu9(AsO4)2(SO4)(OH)10 · 7H2O |
| 3 photos of Forêtite associated with Cyanotrichite | Cu4Al2(SO4)(OH)12 · 2H2O |
| 2 photos of Forêtite associated with Mansfieldite | AlAsO4 · 2H2O |
| 1 photo of Forêtite associated with Olivenite | Cu2(AsO4)(OH) |
| 1 photo of Forêtite associated with Bariopharmacoalumite | Ba0.5Al4(AsO4)3(OH)4 · 4H2O |
| 1 photo of Forêtite associated with Chalcophyllite | Cu18Al2(AsO4)4(SO4)3(OH)24 · 36H2O |
| 1 photo of Forêtite associated with Lavendulan | NaCaCu5(AsO4)4Cl · 5H2O |
| 1 photo of Forêtite associated with Quartz | SiO2 |
| 1 photo of Forêtite associated with Malachite | Cu2(CO3)(OH)2 |
Related Minerals - Strunz-mindat Grouping
| 8.DF. | Wiperamingaite | NaCaFe3+Al(PO4)F5(OH) · H2O |
| 8.DF. | Kernowite | Cu2Fe(AsO4)(OH)4 · 4H2O |
| 8.DF.05 | Hotsonite | Al11(SO4)3(PO4)2(OH)21 · 16H2O |
| 8.DF.10 | Liskeardite | [(Al,Fe)32(AsO4)18(OH)42(H2O)22] · 52H2O |
| 8.DF.10 | Rosièresite | (Pb, Cu, Al, P, O, H) |
| 8.DF.10 | Evansite | Al3(PO4)(OH)6 · 6H2O |
| 8.DF.10 | Bolivarite | Al2(PO4)(OH)3 · 4-5H2O |
| 8.DF.15 | Rusakovite | (Fe3+,Al)5(VO4,PO4)2(OH)9 · 3H2O |
| 8.DF.20 | Liroconite | Cu2Al(AsO4)(OH)4 · 4H2O |
| 8.DF.25 | Sieleckiite | Cu3Al4(PO4)2(OH)12 · 2H2O |
| 8.DF.30 | Chalcophyllite | Cu18Al2(AsO4)4(SO4)3(OH)24 · 36H2O |
| 8.DF.35 | Parnauite | Cu9(AsO4)2(SO4)(OH)10 · 7H2O |
| 8.DF.40 | Gladiusite | Fe2(Fe,Mg)4(PO4)(OH)11(H2O) |
Other Information
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 Forêtite
mindat.org URL:
https://www.mindat.org/min-42728.html
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References for Forêtite
Reference List:
Williams, P. A., Hatert, F., Pasero, M., Mills, S. J. (2012) New minerals and nomenclature modifications approved in 2012. CNMNC Newsletter No 13. Mineralogical Magazine, 76 (3) 807-817 doi:10.1180/minmag.2012.076.3.26
Localities for Forêtite
Showing 6 localities.
symbol to view information about a locality.
The Locality List
- 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).
All localities listed without proper references should be considered as questionable.
France | |
| Mills et al. (2012) |
| Kolitsch (unpubl. data) +4 other references |
| Jean-Marie CLAUDE trouvaille and collection (found 08/1980) | |
| Stephane Maury Collection | |
Italy | |
| Fernando Caboni et al. (2024) |
| Fernando Caboni et al. (2024) |
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Cap Garonne Mine, Le Pradet, Toulon, Var, Provence-Alpes-Côte d'Azur, France