Pecoraite
A valid IMA mineral species
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About Pecoraite
Dr. William Thomas Pecora, Director of the USGS. Served from 1965-1971.
Formula:
Ni3(Si2O5)(OH)4
Colour:
Green, blue-green yellow-green
Lustre:
Vitreous, Waxy, Earthy
Specific Gravity:
3.084
Crystal System:
Monoclinic
Member of:
Name:
For Dr. William Thomas Pecora II (1 February 1913, Belleville, New Jersey, USA - 19 July 1972, Washington, D.C., USA), Director of the United States Geological Survey (from 1965 to 1971) and student of nickel silicate deposits. The William T. Pecora Award was established in 1974 to honour Pecora, and is sponsored jointly by the Department of the Interior and the National Aeronautics and Space Administration (NASA). It is presented annually to individuals or groups that make outstanding contributions toward understanding the Earth by means of remote sensing.
Type Locality:
Dimorph of:
Kaolinite-Serpentine Group
Unique Identifiers
Mindat ID:
3139
Long-form identifier:
mindat:1:1:3139:0
GUID
(UUID V4):
(UUID V4):
7dfc4112-3b13-4e1e-bb7e-7988ffeebf37
IMA Classification of Pecoraite
Approved
IMA Formula:
Ni3Si2O5(OH)4
First published:
1969
Classification of Pecoraite
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
71.1.2d.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
14.26.2
14 : Silicates not Containing Aluminum
26 : Silicates of Ni
14 : Silicates not Containing Aluminum
26 : Silicates of Ni
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 |
|---|---|---|
| Pco | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
| Pco | 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 Pecoraite
Vitreous, Waxy, Earthy
Transparency:
Transparent, Translucent
Colour:
Green, blue-green yellow-green
Density:
3.084 g/cm3 (Measured) 3.47 g/cm3 (Calculated)
Comment:
Measured with absorbed water
Optical Data of Pecoraite
Type:
Biaxial (+/-)
RI values:
nα = 1.565 - 1.603 nβ = 1.565 - 1.603 nγ = 1.565 - 1.603
Max Birefringence:
δ = 0.000
Image shows birefringence interference colour range (at 30µm thickness)
and does not take into account mineral colouration.
and does not take into account mineral colouration.
Surface Relief:
Moderate
Dispersion:
r > v strong
Chemistry of Pecoraite
Mindat Formula:
Ni3(Si2O5)(OH)4
Elements listed:
Common Impurities:
Al,Fe,Mg,Ca,H2O
Crystallography of Pecoraite
Crystal System:
Monoclinic
Cell Parameters:
a = 5.26 Å, b = 9.16 Å, c = 14.7 Å
β = 92°
β = 92°
Ratio:
a:b:c = 0.574 : 1 : 1.605
Unit Cell V:
707.84 ų (Calculated from Unit Cell)
Z:
4
Morphology:
Curved plates, spirals, and tubes, granular, massive.
Comment:
Point Group: n.d.; Space Group: n.d.
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 7.43 Å | (100) |
| 3.66 Å | (75) |
| 1.529 Å | (75) |
| 4.50 Å | (62) |
| 2.620 Å | (62) |
| 2.447 Å | (50) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 5: Initiation of plate tectonics | <3.5-2.5 |
| 38 : Ophiolites | |
| Stage 7: Great Oxidation Event | <2.4 |
| 47i : [Terrestrial weathering of meteorites] |
Geological Setting:
Shears in ultramafic rocks, weathering product of millerite in geodes.
Type Occurrence of Pecoraite
General Appearance of Type Material:
Green grains, 0.1 to 5 mm in diameter, filling cracks a meteorite.
Place of Conservation of Type Material:
National Museum of Natural History, Washington, D.C., USA, 128111.
Geological Setting of Type Material:
Weathered meteorite
Associated Minerals at Type Locality:
Reference:
Faust, G.T., Fahey, J.J., Mason, B., Dwornik, E.J. (1969) Pecoraite, Ni6Si4O10(OH)8, nickel analog of clinochrysotile, formed in the Wolf Creek meteorite. Science: 165: 59-60.
Synonyms of Pecoraite
Other Language Names for Pecoraite
Relationship of Pecoraite to other Species
Member of:
Other Members of this group:
| 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 : P3 1m |
| Fraipontite | (Zn,Al)3((Si,Al)2O5)(OH)4 | Mon. |
| 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 : P3 1m |
| Népouite | Ni3Si2O5(OH)4 | Orth. |
Common Associates
Associated Minerals Based on Photo Data:
| 6 photos of Pecoraite associated with Nullaginite | Ni2(CO3)(OH)2 |
| 5 photos of Pecoraite associated with Gaspéite | NiCO3 |
| 4 photos of Pecoraite associated with Millerite | NiS |
| 2 photos of Pecoraite associated with Talc | Mg3Si4O10(OH)2 |
| 2 photos of Pecoraite associated with Serpentine Subgroup | D3[Si2O5](OH)4 |
| 2 photos of Pecoraite associated with Garnierite | |
| 2 photos of Pecoraite associated with Cinnabar | HgS |
| 2 photos of Pecoraite associated with Quartz | SiO2 |
| 1 photo of Pecoraite associated with Rammelsbergite | NiAs2 |
| 1 photo of Pecoraite associated with Willemseite | Ni3Si4O10(OH)2 |
Related Minerals - Strunz-mindat Grouping
| 9.ED. | Clinochrysotile | |
| 9.ED.05 | Dickite | Al2(Si2O5)(OH)4 |
| 9.ED.05 | Kaolinite | Al2(Si2O5)(OH)4 |
| 9.ED.05 | Nacrite | 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 | Al2(Si2O5)(OH)4 |
| 9.ED.10 | Hisingerite | Fe3+2(Si2O5)(OH)4 · 2H2O |
| 9.ED.10 | Hydrohalloysite | Al2Si2O5(OH)4 · 2H2O |
| 9.ED.15 | Amesite | Mg2Al(AlSiO5)(OH)4 |
| 9.ED.15 | Antigorite | Mg3(Si2O5)(OH)4 |
| 9.ED.15 | Berthierine | (Fe2+,Fe3+,Al)3(Si,Al)2O5(OH)4 |
| 9.ED.15 | Brindleyite | (Ni,Al)3(Si,Al)2O5(OH)4 |
| 9.ED.15 | Caryopilite | Mn2+3Si2O5(OH)4 |
| 9.ED.15 | Cronstedtite | Fe2+2Fe3+((Si,Fe3+)2O5)(OH)4 |
| 9.ED.15 | Fraipontite | (Zn,Al)3((Si,Al)2O5)(OH)4 |
| 9.ED.15 | Greenalite | (Fe2+,Fe3+)2-3Si2O5(OH)4 |
| 9.ED.15 | Kellyite | Mn2+2Al(AlSiO5)(OH)4 |
| 9.ED.15 | Lizardite | Mg3(Si2O5)(OH)4 |
| 9.ED.15 | Manandonite | Li2Al4(Si2AlB)O10(OH)8 |
| 9.ED.15 | Népouite | Ni3Si2O5(OH)4 |
| 9.ED.15 | Guidottiite | Mn2Fe3+(Fe3+SiO5)(OH)4 |
| 9.ED.15 va | Chromoamesite | Mg2(Al,Cr)(AlSiO5)(OH)4 |
| 9.ED.20 | Allophane | (Al2O3)(SiO2)1.3-2 · 2.5-3H2O |
| 9.ED.20 | Chrysocolla | Cu2-xAlx(H2-xSi2O5)(OH)4 · nH2O, x < 1 |
| 9.ED.20 | Imogolite | Al2SiO3(OH)4 |
| 9.ED.20 | Neotocite | (Mn,Fe,Mg)SiO3 · H2O |
| 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
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 Pecoraite
mindat.org URL:
https://www.mindat.org/min-3139.html
Please feel free to link to this page.
Please feel free to link to this page.
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External Links:
Mineral Dealers:
References for Pecoraite
Reference List:
Localities for Pecoraite
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 | |
| Anderson et al. (2002) |
| Nickel et al. (1981) |
| Nickel et al. (1993) +1 other reference |
| Nickel +2 other references |
| Faust et al. (1969) +2 other references |
| Nickel et al. (1981) +1 other reference |
Canada | |
| Tarassoff (1994) |
Dominican Republic | |
| M.E. Ciriotti (Steffen Moeckel analysis) |
France | |
| Berger +1 other reference |
| Berger +1 other reference |
| Mandarino (2001) |
Germany | |
| Tröger (2012) |
| Andreas Gerstenberg collection |
| M Adelt collection |
Greece | |
| Möckel (2000) |
Italy | |
| Biagioni et al. (2020) |
| Bedognè et al. (1993) |
| Bedognè et al. (1993) |
| Bedognè et al. (1993) +1 other reference | |
| Lapis (10) | |
| Guicciardi (1980) |
| Boscardin et al. (2013) |
| Lecca G.C. et al. (2022) |
| Marco Bonifazi collection |
| Orlandi (2011) |
Morocco | |
| Färber (n.d.) |
Russia | |
| Berger +2 other references |
| Talovina et al. (2008) | |
| Talovina et al. (2003) | |
| Pavel.M. Kartashov (n.d.) |
| Talovina et al. (2008) |
| ... | |
South Africa | |
| Cairncross et al. (1995) |
South Korea | |
| Song et al. (1995) +1 other reference |
| Song et al. (1995) | |
Turkey | |
| Helvaci et al. (2013) |
USA | |
| Anthony et al. (1995) |
| Dunning et al. (2005) |
| |
| Tim Greenland (2011) |
| Parker (2014) |
| Travis Olds collection |
| George W. Robinson and S.M. Carlson (2009) | |
| Sherwood et al. (1998) |
| www.gswweb.org/minutes/GSW1980.htm | |
| Sherwood et al. (1998) | |
| Robinson et al. (2007) |
| ... |
| Rocks & Min. Vol. 71 (1996) |
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Malenco Valley, Sondrio Province, Lombardy, Italy