Purpurite
A valid IMA mineral species - grandfathered
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About Purpurite
Formula:
Mn3+(PO4)
Purpurite forms by leaching of Li out of its site leaving a vacancy and by oxidation of divalent Mn. Thus, the formula may also be given as ◻Mn3+(PO4)
Colour:
Dark purple to purplish red
Lustre:
Dull, Earthy
Hardness:
4 - 4½
Specific Gravity:
3.2 - 3.4
Crystal System:
Orthorhombic
Member of:
Name:
Named in 1905 by Louis C. Graton and Waldemar T. Schaller from the Latin "purpura" in allusion to its colour.
Type Locality:
Isostructural with:
Triphylite Group, Heterosite-Purpurite Series
Purpurite is the trivalent Mn-dominant, Li-deficient oxidation product of lithiophilite. The species of the Heterosite-Purpurite Series are secondary minerals formed by oxidation of iron and or manganese with the simultaneous leaching of lithium, primarily from their respective parent species, lithiophilite and triphylite. Intermediate alteration products are part of a continuous process of alteration: Ferrisicklerite and Sicklerite, are intermediate between unoxidized and unleached end-members and the completely leached and appropriately oxidized end-products, but may not be valid species. The Mn:Fe value has not been observed to vary much from the primary lithiophilite to the secondary purpurite. Purpurite is far less common than its look-alike species, heterosite. Purpurite is frequently artificially colored bright purple through acid etching.
Visit gemdat.org for gemological information about Purpurite.
Purpurite is the trivalent Mn-dominant, Li-deficient oxidation product of lithiophilite. The species of the Heterosite-Purpurite Series are secondary minerals formed by oxidation of iron and or manganese with the simultaneous leaching of lithium, primarily from their respective parent species, lithiophilite and triphylite. Intermediate alteration products are part of a continuous process of alteration: Ferrisicklerite and Sicklerite, are intermediate between unoxidized and unleached end-members and the completely leached and appropriately oxidized end-products, but may not be valid species. The Mn:Fe value has not been observed to vary much from the primary lithiophilite to the secondary purpurite. Purpurite is far less common than its look-alike species, heterosite. Purpurite is frequently artificially colored bright purple through acid etching.
Visit gemdat.org for gemological information about Purpurite.Unique Identifiers
Mindat ID:
3311
Long-form identifier:
mindat:1:1:3311:0
GUID
(UUID V4):
(UUID V4):
71e759ad-91bb-4b7a-a0ba-2d6ce065fd27
IMA Classification of Purpurite
Approved, 'Grandfathered' (first described prior to 1959)
First published:
1905
Classification of Purpurite
8.AB.10
8 : PHOSPHATES, ARSENATES, VANADATES
A : Phosphates, etc. without additional anions, without H2O
B : With medium-sized cations
8 : PHOSPHATES, ARSENATES, VANADATES
A : Phosphates, etc. without additional anions, without H2O
B : With medium-sized cations
38.4.1.2
38 : ANHYDROUS NORMAL PHOSPHATES, ARSENATES, AND VANADATES
4 : AXO4
38 : ANHYDROUS NORMAL PHOSPHATES, ARSENATES, AND VANADATES
4 : AXO4
19.12.11
19 : Phosphates
12 : Phosphates of Mn
19 : Phosphates
12 : Phosphates of Mn
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 |
|---|---|---|
| Pur | 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 Purpurite
Dull, Earthy
Transparency:
Opaque
Comment:
Luster of fresh fracture surfaces is satiny; dull on altered surfaces.
Colour:
Dark purple to purplish red
Comment:
Dark brown to brown-black on altered surfaces.
Streak:
Light to medium purple, lighter than the colour of the massive mineral.
Hardness:
4 - 4½ on Mohs scale
Tenacity:
Brittle
Cleavage:
Distinct/Good
On {100}, good; on {010}, imperfect. Cleavage surfaces curved or crinkled at times.
On {100}, good; on {010}, imperfect. Cleavage surfaces curved or crinkled at times.
Fracture:
Irregular/Uneven
Density:
3.2 - 3.4 g/cm3 (Measured) 3.69 g/cm3 (Calculated)
Optical Data of Purpurite
Type:
Biaxial (+)
RI values:
nα = 1.852(2) nβ = 1.862(2) nγ = 1.922(2)
2V:
Measured: 38° , Calculated: 38°
Birefringence:
0.040
Max Birefringence:
δ = 0.070
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:
Very High
Dispersion:
Moderate
Optical Extinction:
Parallel
Pleochroism:
Strong
Comments:
X = Greenish gray, gray to rose-red
Y = Deep blood-red to purplish red
Z = Deep blood-red to purplish red
Y = Deep blood-red to purplish red
Z = Deep blood-red to purplish red
Comments:
Z = Y > X. Also Z > Y >> X. Optic axis sections may exhibit anomalous green interference colours.
Chemistry of Purpurite
Mindat Formula:
Mn3+(PO4)
Purpurite forms by leaching of Li out of its site leaving a vacancy and by oxidation of divalent Mn. Thus, the formula may also be given as ◻Mn3+(PO4)
Purpurite forms by leaching of Li out of its site leaving a vacancy and by oxidation of divalent Mn. Thus, the formula may also be given as ◻Mn3+(PO4)
Elements listed:
Common Impurities:
Fe
Crystallography of Purpurite
Crystal System:
Orthorhombic
Class (H-M):
mmm (2/m 2/m 2/m) - Dipyramidal
Space Group:
Pmna
Cell Parameters:
a = 5.8237(6) Å, b = 9.766(1) Å, c = 4.7771(5) Å
Ratio:
a:b:c = 0.596 : 1 : 0.489
Unit Cell V:
271.69 ų (Calculated from Unit Cell)
Z:
4
Morphology:
Massive, cleavage fragments to 20 cm.
Comment:
Pmnb setting chosen to show relationship to the olivine structure
Crystal Structure
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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) |
|---|---|---|---|---|---|---|---|
| 0018097 | Purpurite | Bjoerling C, Westgren A (1938) Minerals of the Varutrask pegmatite. IX. X-ray studies on triphylite, varulite, and their oxidation products _cod_database_code 1011230 Geologiska Foreningens i Stockholm Forhandlingar 60 67-72 | 1938 | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 4.883 Å | (70) |
| 4.293 Å | (100) |
| 3.455 Å | (65) |
| 2.946 Å | (60) |
| 2.912 Å | (60) |
| 2.4433 Å | (70) |
| 2.4099 Å | (30) |
Comments:
ICDD 37-478
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 4b: Highly evolved igneous rocks | >3.0 |
| 34 : Complex granite pegmatites | |
| Stage 7: Great Oxidation Event | <2.4 |
| 47c : [Carbonates, phosphates, borates, nitrates] | |
| 47h : [Near-surface oxidized, dehydrated minerals] | |
| Stage 10a: Neoproterozoic oxygenation/terrestrial biosphere | <0.6 |
| 52 : Guano- and urine-derived minerals | <0.4 |
Geological Setting:
Primarily an alteration product of lithiophylite in complex granitic pegmatites, rarely from the reaction of bat guano, Fe-Mn deposits and sea water.
Type Occurrence of Purpurite
General Appearance of Type Material:
Small irregular masses. Narrow lenses or veinlets.
Place of Conservation of Type Material:
National Museum of Natural History (Smithsonian Institution), Washington, D.C., USA, number 93883.
Geological Setting of Type Material:
Oxidized and leached primary lithiophilite pods from a granite pegmatite.
Associated Minerals at Type Locality:
Synonyms of Purpurite
Other Language Names for Purpurite
Relationship of Purpurite to other Species
Member of:
Other Members of this group:
| Heterosite | (Fe3+,Mn3+)PO4 | Orth. mmm (2/m 2/m 2/m) : Pmna |
| Karenwebberite | NaFe2+PO4 | Orth. mmm (2/m 2/m 2/m) : Pnma |
| Lithiophilite | LiMn2+PO4 | Orth. mmm (2/m 2/m 2/m) : Pmna |
| Natrophilite | NaMn2+PO4 | Orth. mmm (2/m 2/m 2/m) : Pmna |
| Simferite | LiMg(PO4) | Orth. |
| Triphylite | LiFe2+PO4 | Orth. mmm (2/m 2/m 2/m) : Pmna |
Forms a series with:
Common Associates
Associated Minerals Based on Photo Data:
| 15 photos of Purpurite associated with Alluaudite | (Na,Ca)Mn2+(Fe3+,Mn2+,Fe2+,Mg)2(PO4)3 |
| 13 photos of Purpurite associated with Lithiophilite | LiMn2+PO4 |
| 11 photos of Purpurite associated with Heterosite | (Fe3+,Mn3+)PO4 |
| 7 photos of Purpurite associated with Cleavelandite | Na(AlSi3O8) |
| 7 photos of Purpurite associated with Quartz | SiO2 |
| 6 photos of Purpurite associated with Triphylite | LiFe2+PO4 |
| 6 photos of Purpurite associated with Rockbridgeite | Fe2+Fe3+4(PO4)3(OH)5 |
| 5 photos of Purpurite associated with Sicklerite | Li1-x(Mn3+xMn2+1-x)PO4 |
| 5 photos of Purpurite associated with Natrophilite | NaMn2+PO4 |
| 5 photos of Purpurite associated with Triplite | Mn2+2(PO4)F |
Related Minerals - Strunz-mindat Grouping
| 8.AB. | Rodolicoite | Fe3+PO4 |
| 8.AB. | Johanngeorgenstadtite | Ni2+4.5(AsO4)3 |
| 8.AB. | Borisenkoite | Cu3[(V,As)O4]2 |
| 8.AB. | Niasite | Ni2+4.5(AsO4)3 |
| 8.AB. | Olsenite | KFe4(PO4)3 |
| 8.AB. | Karwowskiite | Ca9Mg(Fe2+0.5◻0.5)(PO4)7 |
| 8.AB.05 | Farringtonite | Mg3(PO4)2 |
| 8.AB.10 | Ferrisicklerite | Li1-x(Fe3+xFe2+1-x)PO4 |
| 8.AB.10 | Heterosite | (Fe3+,Mn3+)PO4 |
| 8.AB.10 | Lithiophilite | LiMn2+PO4 |
| 8.AB.10 | Natrophilite | NaMn2+PO4 |
| 8.AB.10 | Sicklerite | Li1-x(Mn3+xMn2+1-x)PO4 |
| 8.AB.10 | Simferite | LiMg(PO4) |
| 8.AB.10 | Triphylite | LiFe2+PO4 |
| 8.AB.10 | Karenwebberite | NaFe2+PO4 |
| 8.AB.15 | Sarcopside | Fe2+3(PO4)2 |
| 8.AB.15 | Chopinite | Mg3(PO4)2 |
| 8.AB.15 | Zavalíaite | Mn2+3(PO4)2 |
| 8.AB.20 | Beusite | Mn2+Mn2+2 (PO4)2 |
| 8.AB.20 | Graftonite | Fe2+Fe2+2(PO4)2 |
| 8.AB.20 | Graftonite-(Ca) | CaFe2+2(PO4)2 |
| 8.AB.20 | Graftonite-(Mn) | MnFe2+2(PO4)2 |
| 8.AB.20 | Beusite-(Ca) | CaMn2+2(PO4)2 |
| 8.AB.25 | Xanthiosite | Ni3(AsO4)2 |
| 8.AB.30 | Lammerite | Cu3(AsO4)2 |
| 8.AB.30 | Paralammerite | Cu3(AsO4)2 |
| 8.AB.35 | Mcbirneyite | Cu3(VO4)2 |
| 8.AB.35 | Stranskiite | Zn2Cu(AsO4)2 |
| 8.AB.35 | Pseudolyonsite | Cu3(VO4)2 |
| 8.AB.40 | Lyonsite | Cu3Fe4(VO4)6 |
| 8.AB.40 | Michalskiite | Fe3+1.33Cu2+2(MgFe3+)2(VO4)6 |
Fluorescence of Purpurite
Not fluorescent in UV
Other Information
Notes:
Readily soluble in HCl.
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 Purpurite
mindat.org URL:
https://www.mindat.org/min-3311.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 Purpurite
Reference List:
Larsen, Esper S. (1921) The microscopic determination of the nonopaque minerals. Bulletin Vol. 679. US Geological Survey doi:10.3133/b679 p.124
Localities for Purpurite
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.
Argentina | |
| Černý et al. (2011) |
Australia | |
| Personally collected inside adit of ... |
| Eagle et al. (2015) |
| Jacobson et al. (2007) |
| American Mineralogist (1928) +2 other references | |
| Simpson (1928) +1 other reference |
| Jacobson et al. (2007) |
Austria | |
| Niedermayr et al. (1995) |
Brazil | |
| Menezes Filho et al. (2019) |
| Martins da Pedra collection | |
| Atencio et al. (2006) |
| Amores Casals et al. (2014) |
Canada | |
| Phillips (1978) |
| Bannatyne (1985) | |
| Bannatyne (1985) | |
| Phillips (1978) | |
| Bannatyne (1985) | |
| Bannatyne (1985) | |
| Bannatyne (1985) |
| Bannatyne (1985) |
| Groat et al. (2003) |
| Tindle et al. (2002) |
| Hewitt (1967) |
China | |
| Zhiguo Liu et al. (2005) |
| Chaoyang Li et al. (2003) |
Czech Republic | |
| Černý et al. (Weisser Stein) |
Finland | |
| Teertstra et al. (1993) |
| Ilkka Mikkola collection |
France | |
| Palache et al. (1951) |
| Inventaire mineralogique de l'Ariege (Editions BRGM 1984) |
Germany | |
| Obermüller et al. (1993) |
| |
Italy | |
| Gramaccioli C.M. (1975) |
Namibia | |
| [Schumann +1 other reference |
| Mineralogical Research Co. specimen |
| Keller (1991) +2 other references |
| von Bezing (2007) +1 other reference |
| |
| von Bezing (2007) |
Poland | |
| Pieczka et al. (2015) +1 other reference |
| Pieczka et al. (2013) +3 other references |
Portugal | |
| Schnorrer-Köhler (1991) |
| |
| Self-collected by Pedro Alves. |
| |
| |
Romania | |
| Calin N et al. (2014) |
Russia | |
| Kassandrov et al. (2009) |
| Kassandrov et al. (2009) | |
Rwanda | |
| Royal Museum for Central Africa |
| Gallagher et al. (1963) +1 other reference |
South Africa | |
| Cairncross et al. (1995) |
| Cairncross et al. (1995) |
Spain | |
| Encarnación Roda-Robles (2007) +1 other reference |
| & locality references +1 other reference |
| Bareche (2005) |
Sweden | |
| Sandström (2008) |
USA | |
| Jahns (1952) +1 other reference |
| Jahns (1952) |
| Jahns (1952) | |
| Mineralogical Record 33 (5) +1 other reference |
| Fisher (2002) | |
| Weber (1963) +1 other reference | |
| King (2000) +1 other reference |
| Kunz (1906) +2 other references | |
| Kunz (1906) +1 other reference | |
| Fisher (2002) |
| San Diego Mining Company (2022) | |
| Palache et al. (1951) | |
| Betts (n.d.) |
| Rocks & Min.:62:234-235. | |
| - (2005) | |
| Eckel et al. (1997) | |
| Hanley et al. (1950) +1 other reference | |
| Hanley et al. (1950) +1 other reference | |
| Eckel et al. (1997) |
| Sloto (1989) |
| Shainin (1946) |
| Schooner (circa 1985) +1 other reference |
| |
| |
| King et al. (1994) |
| Collected by Clifford Trebilcock +2 other references |
| King (2000) |
| King et al. (1994) |
| Falster et al. (2019) |
| King (2000) |
| King et al. (1994) +2 other references |
| Pollucite from Ryerson Hill. Collected ... +3 other references | |
| King et al. (1994) +1 other reference |
| Cameron +2 other references | |
| |
| Billings et al. (1944) |
| Kevin Czaja Collection |
| Morrill |
| Morrill +1 other reference |
| Cameron et al. (1954) |
| Cameron et al. (1954) |
| Cameron et al. (1954) |
| King (2000) |
| Kesler |
| Palache et al. (1951) |
| K.Linnekin collection |
| Smith et al. (2000) +1 other reference |
| Roberts et al. (1965) +1 other reference |
| Roberts et al. (1965) | |
| Staatz +3 other references |
| - (2005) | |
| |
| USGS Bull 380D |
| Falster et al. (1988) |
Quick NavTopAbout PurpuriteUnique IdentifiersIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography Crystal StructureX-Ray Powder DiffractionGeological EnvironmentType Occurrence SynonymsOther LanguagesRelationshipsCommon AssociatesStrunz-MindatFluorescence Other InformationInternet Links References Localities Locality List
Cameroon pegmatite, Goabeb Farm 63, Karibib Constituency, Erongo Region, Namibia