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Fraipontite
A valid IMA mineral species - grandfathered
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About Fraipontite
Julien J.J. Fraipont
Formula:
(Zn,Al)3((Si,Al)2O5)(OH)4
May contain some Cu.
Colour:
Yellowish white to bluish
Lustre:
Silky
Hardness:
3½ - 4
Specific Gravity:
3.08 - 3.10
Crystal System:
Monoclinic
Member of:
Name:
Named in 1927 by Giuseppe Raimondo Pio Cesàro (1849-1939) in honour of Julien Jean Joseph Fraipont (17 August 1857, Liège, Belgium — 22 March 1910, Liège, Belgium), paleontologist and professor of zoology at the University of Liège and noted for his work on Neanderthal man and in honor of his son, Charles Marie Joseph Julien Fraipont (21 March 1883, Chênée, Liège, Belgium — 15 April 1946, Forest, near Frasnes-lez-Anvaing, Belgium), professor of paleontology at the University of Liège, who also studied Neanderthal man, as well as subjects in his specialty of phytopaleontology.
Co-Type Localities:
Isostructural with:
Compare sauconite and zincsilite.
See also Unnamed (Cu analogue of Fraipontite).
Charge-balanced ideal formula: (Zn2Al)(AlSi)O5(OH)4
See also Unnamed (Cu analogue of Fraipontite).
Charge-balanced ideal formula: (Zn2Al)(AlSi)O5(OH)4
Unique Identifiers
Mindat ID:
1588
Long-form identifier:
mindat:1:1:1588:8
IMA Classification of Fraipontite
Approved, 'Grandfathered' (first described prior to 1959)
IMA Formula:
(Zn2+,Al)3(Si,Al)2O5(OH)4
First published:
1927
Classification of Fraipontite
9.ED.15
9 : SILICATES (Germanates)
E : Phyllosilicates
D : Phyllosilicates with kaolinite layers composed of tetrahedral and octahedral nets
9 : SILICATES (Germanates)
E : Phyllosilicates
D : Phyllosilicates with kaolinite layers composed of tetrahedral and octahedral nets
71.1.2c.4
71 : PHYLLOSILICATES Sheets of Six-Membered Rings
1 : Sheets of 6-membered rings with 1:1 layers
71 : PHYLLOSILICATES Sheets of Six-Membered Rings
1 : Sheets of 6-membered rings with 1:1 layers
16.12.16
16 : Silicates Containing Aluminum and other Metals
12 : Aluminosilicates of Sr, Ba and Zn
16 : Silicates Containing Aluminum and other Metals
12 : Aluminosilicates of Sr, Ba and Zn
Mineral Symbols
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.
Please only use the official IMA–CNMNC symbol. Older variants are listed for historical use only.
| Symbol | Source | Reference for Standard |
|---|---|---|
| Fpt | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
| Fpt | Warr (2020) | Warr, L.N. (2020) Recommended abbreviations for the names of clay minerals and associated phases. Clay Minerals, 55, 261–264 doi:10.1180/clm.2020.30 |
Physical Properties of Fraipontite
Silky
Transparency:
Translucent, Opaque
Colour:
Yellowish white to bluish
Streak:
White, pale green
Hardness:
3½ - 4 on Mohs scale
Density:
3.08 - 3.10 g/cm3 (Measured) 3.49(5) g/cm3 (Calculated)
Optical Data of Fraipontite
Type:
Biaxial (-)
RI values:
nα = 1.620 nβ = 1.624 nγ = 1.624
2V:
Measured: 15° to 20°
Max. Birefringence:
δ = 0.004
Based on recorded range of RI values above.
Based on recorded range of RI values above.
Interference Colours:
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
Surface Relief:
High (positive)
Relative to Canada balsam mounting medium (n ≈ 1.537).
Relative to Canada balsam mounting medium (n ≈ 1.537).
This shows the grain boundary and Becke line effect under plane-polarised
light, based on the contrast between this mineral's average refractive
index and the mounting medium. It does not take into account mineral
colouration.
In focus
Interference Figure:
This shows the idealized biaxial acute bisectrix (Bxa) interference figure
- the conoscopic view for a grain cut perpendicular to the acute bisectrix, using
this mineral's 2V. The two small white dots mark the melatopes - the points
where the two optic axes emerge - and are shown only when they fall within the
field of view. The coloured bands are isochromatics, and the dark bands are
isogyres.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
Dispersion:
r < v strong
Chemistry of Fraipontite
Mindat Formula:
(Zn,Al)3((Si,Al)2O5)(OH)4
May contain some Cu.
May contain some Cu.
Element Weights:
Common Impurities:
Fe,Cu,Mg,Ca,K
Crystallography of Fraipontite
Crystal System:
Monoclinic
Cell Parameters:
a = 5.34 Å, b = 9.21 Å, c = 14.12 Å
β = 93.2°
β = 93.2°
Ratio:
a:b:c = 0.58 : 1 : 1.533
Unit Cell V:
693.36 ų (Calculated from Unit Cell)
Z:
4
Comment:
Point Group: n.d.; Space Group: n.d.
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 7.03 Å | (100) |
| 4.60 Å | (20) |
| 3.53 Å | (70) |
| 2.650 Å | (40) |
| 2.490 Å | (30) |
| 2.385 Å | (30) |
| 1.540 Å | (30) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 7: Great Oxidation Event | <2.4 |
| 47a : [Near-surface hydration of prior minerals] |
Type Occurrence of Fraipontite
Co-Type Localities:
General Appearance of Type Material:
Crusts of fibers 4-10 mm thick on smithsonite
Place of Conservation of Type Material:
University of Liège, Liège, Belgium, 13727.
Associated Minerals at Type Locality:
Synonyms of Fraipontite
Other Language Names for Fraipontite
Varieties of Fraipontite
| Copper-bearing Fraipontite | A copper-bearing variety of fraipontite. |
Relationship of Fraipontite to other Species
Member of:
Other Members of Serpentine Subgroup:
| Amesite | Mg2Al(AlSiO5)(OH)4 | Tric. 1 : P1 |
| Antigorite | Mg3(Si2O5)(OH)4 | Mon. m : Bm |
| Berthierine | (Fe2+,Fe3+,Al)3(Si,Al)2O5(OH)4 | Mon. m : Bm |
| Brindleyite | (Ni,Al)3(Si,Al)2O5(OH)4 | Mon. |
| Caryopilite | Mn2+3Si2O5(OH)4 | Mon. |
| Chrysotile | Mg3(Si2O5)(OH)4 | Mon. m : Bb |
| Cronstedtite | Fe2+2Fe3+((Si,Fe3+)2O5)(OH)4 | Trig. 3m : P31m |
| Guidottiite | Mn2Fe3+(Fe3+SiO5)(OH)4 | Hex. 6 : P63 |
| Kellyite | Mn2+2Al(AlSiO5)(OH)4 | Hex. 6 : P63 |
| Lizardite | Mg3(Si2O5)(OH)4 | Trig. 3m : P31m |
| Népouite | Ni3Si2O5(OH)4 | Orth. |
| Pecoraite | Ni3(Si2O5)(OH)4 | Mon. |
Common Associates
Associations Based on Photo Data:
| 8 photos of Fraipontite associated with Wulfenite | Pb(MoO4) |
| 6 photos of Fraipontite associated with Galena | PbS |
| 5 photos of Fraipontite associated with Aurichalcite | (Zn,Cu)5(CO3)2(OH)6 |
| 3 photos of Fraipontite associated with Smithsonite | ZnCO3 |
| 3 photos of Fraipontite associated with Quartz | SiO2 |
| 3 photos of Fraipontite associated with Jarosite | KFe3+3(SO4)2(OH)6 |
| 2 photos of Fraipontite associated with Zálesíite | CaCu6(AsO4)2(AsO3OH)(OH)6 · 3H2O |
| 2 photos of Fraipontite associated with Todorokite | (Na,Ca,K,Ba,Sr)1-x(Mn,Mg,Al)6O12 · 3-4H2O |
| 2 photos of Fraipontite associated with Baryte | BaSO4 |
| 2 photos of Fraipontite associated with Aragonite | CaCO3 |
Related Minerals - Strunz-mindat Grouping
| 9.ED. | 'Clinochrysotile' | Mg3(Si2O5)(OH)4 |
| 9.ED.05 | Dickite | Al2(Si2O5)(OH)4 |
| 9.ED.05 | Nacrite | Al2(Si2O5)(OH)4 |
| 9.ED.05 | Kaolinite | Al2(Si2O5)(OH)4 |
| 9.ED.05 | Odinite | (Fe,Mg,Al,Fe,Ti,Mn)2.4((Si,Al)2O5)(OH)4 |
| 9.ED.10 | Halloysite | Al2Si2O5(OH)4 · n(H2O) |
| 9.ED.10 | Hisingerite | Fe3+2(Si2O5)(OH)4 · 2H2O |
| 9.ED.10 | 'Hydrohalloysite' | Al2Si2O5(OH)4 · 2H2O |
| 9.ED.15 | Antigorite | Mg3(Si2O5)(OH)4 |
| 9.ED.15 | Brindleyite | (Ni,Al)3(Si,Al)2O5(OH)4 |
| 9.ED.15 | Népouite | Ni3Si2O5(OH)4 |
| 9.ED.15 | Pecoraite | Ni3(Si2O5)(OH)4 |
| 9.ED.15 | Guidottiite | Mn2Fe3+(Fe3+SiO5)(OH)4 |
| 9.ED.15 | Lizardite | Mg3(Si2O5)(OH)4 |
| 9.ED.15 | Berthierine | (Fe2+,Fe3+,Al)3(Si,Al)2O5(OH)4 |
| 9.ED.15 | Kellyite | Mn2+2Al(AlSiO5)(OH)4 |
| 9.ED.15 | Cronstedtite | Fe2+2Fe3+((Si,Fe3+)2O5)(OH)4 |
| 9.ED.15 | Caryopilite | Mn2+3Si2O5(OH)4 |
| 9.ED.15 | Amesite | Mg2Al(AlSiO5)(OH)4 |
| 9.ED.15 | Greenalite | (Fe2+,Fe3+)2-3Si2O5(OH)4 |
| 9.ED.15 | Manandonite | Li2Al4(Si2AlB)O10(OH)8 |
| 9.ED.20 | Chrysocolla | Cu2-xAlx(H2-xSi2O5)(OH)4 · nH2O, x < 1 |
| 9.ED.20 | Neotocite | (Mn,Fe)SiO3 · H2O (?) |
| 9.ED.20 | Allophane | (Al2O3)(SiO2)1.3-2 · 2.5-3H2O |
| 9.ED.20 | Imogolite | Al2SiO3(OH)4 |
| 9.ED.25 | Bismutoferrite | Fe3+2Bi(SiO4)2(OH) |
| 9.ED.25 | Chapmanite | Fe3+2Sb3+(Si2O5)O3(OH) |
| 9.ED.30 | 'Pianlinite' | Al2Si2O6(OH)2 |
Other Information
Notes:
Easily and completely soluble in nitric acid. Gelatinizes upon evaporation. Fuses easily to a white enamel.
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 Fraipontite
mindat.org URL:
https://www.mindat.org/min-1588.html
Please feel free to link to this page.
Please feel free to link to this page.
Search Engines:
External Links:
Mineral Dealers:
References for Fraipontite
Reference List:
Fransolet, André-Mathieu; Bourguignon, Pol (1975) Données nouvelles sur la fraipontite de Moresnet (Belgique). Bulletin de la Société française de Minéralogie et de Cristallographie, 98 (4). 235-244 doi:10.3406/bulmi.1975.6994
Young, B., Livingstone, A., Thomson, N. (1992) Fraipontite from Wensleydale, North Yorkshire. Proceedings of the Yorkshire Geological
Society, 49 (2). 125-127 doi:10.1144/pygs.49.2.125
Localities for Fraipontite
Showing 69 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.
Australia | |
| Francis (2010) |
| Bottrill et al. (2008) |
Austria | |
| Niedermayr (1987) |
Belgium (TL) | |
| Cesàro (1883) +4 other references |
| Joan Rosell |
| Mélon et al. (1976) +1 other reference | |
Chile | |
| maurzi |
Cuba | |
| Torró et al. (2016) |
France | |
| Queneau (n.d.) |
| André Melle collection; EDX analysis V. Bourgoin (AJW, Paris) |
Germany | |
| Wrede (2019) |
| Wittern (2001) |
| Schnorrer (1995) +1 other reference | |
Greece | |
| |
| |
| Rieck et al. (1999) |
| Rieck (n.d.) |
Italy | |
| Orlandi et al. (2007) +1 other reference |
| //doi.org/10.57635/MICRO.2025.23.16 |
| A.Costantini (2015) |
| Orlandi et al. (2009) |
| Merlino et al. (2001) +2 other references |
Kazakhstan (TL) | |
| Chukrov (1956) +1 other reference |
| |
| Chukrov (1956) |
Mexico | |
| Gazquez et al. (1) |
Morocco | |
| Choulet et al. (2016) |
Namibia | |
| Gebhard (1999) |
Peru | |
| Arfè et al. (2017) +1 other reference |
Portugal | |
| Silva et al. (2026) |
| Pedro Alves analytical data |
Romania | |
| minerals-of-the-carpathians.eu (2008) |
| Hîrtopanu (1997) +1 other reference |
Spain | |
| Calvo Rebollar et al. (2022) |
| Favreau (n.d.) |
| Calvo Rebollar (2018) |
| Calvo Rebollar (2018) |
| Calvo et al. (2007) |
Switzerland | |
| Ansermet (2012) |
Turkmenistan | |
| Vladimir A. Maltsev (1993) +2 other references |
UK | |
| Pluth et al. (2005) |
| Daltry et al. (1994) |
| Day (1999) |
| Plant et al. (1996) |
USA | |
| Foord et al. (1983) +1 other reference |
| [var: Copper-bearing Fraipontite] Foord et al. (1983) +1 other reference | |
| Carnegie Museum of Natural History ... |
| 1 +1 other reference |
| Robert M. Housley (2005) |
| Wise (1993) |
| Thorne (n.d.) |
| Collected by and in the collection of ... | |
| Hayes et al. (2008) |
| Barrick Gold Corporation |
| Newmont Mining Corporation |
| Castor et al. (2004) |
| Castor et al. (2004) |
| Chukrov (1956) +1 other reference |
| Luetcke (n.d.) |
| R. D. Green photo | |
| NMBMMR New Mexico Mineral symposium (2003) |
| Northrop et al. (1996) |
| Northrop et al. (1996) |
| Jerry Cone Collection | |
| Tiny Minerals | |
| Northrop et al. (1996) |
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Dives Mine, Silver Mining District, La Paz County, Arizona, USA