Crocoite
A valid IMA mineral species - grandfathered
This page kindly sponsored by PH, dedicated to JULIA ROSE HUGGINS
About Crocoite
Formula:
PbCr6+O4
Colour:
Orange, red, yellow; orange-red in transmitted light.
Lustre:
Sub-Adamantine, Sub-Vitreous, Resinous, Waxy
Hardness:
2½ - 3
Specific Gravity:
5.97 - 6.02
Crystal System:
Monoclinic
Member of:
Name:
Originally recognized by Mikhail Vassil’evich Lomonosov in 1763 as a red lead ore. Johann Gottlob Lehmann in 1766 named it Nova Minera Plumbi. Various authors later gave the mineral a name signifying the presence of lead and the color red: minera plumbi rubra (Wallerius, 1778), Rothes bleierz (Werner, 1774), and Plomb rouge (Macquart, 1789). After the element chromium was announced in 1798, a new series of names was applied to the species: Plomb chromaté (Haüy, 1801), Kallochrom (Hausmann, 1813), etc. Renamed Crocise by François Sulpice Beudant in 1832 and Krokoisite by Franz von Kobell in 1838. Translated to the current pronunciation, Krokoit, by Johann August Breithaupt in 1841. Named Beresofite in 1844 by Charles Upham Shepard. Named Lehmannite by Henry J. Brooke and William H. Miller in 1852. The name crocoite comes from the Greek κρόκος "crocon" = saffron, alluding to the saffron-orange color of its powder.
Crocoite is commonly found as crystals, usually as long prismatic crystals and more rarely as equant crystals, but are most often poorly terminated, and are usually of a bright hyacinth-red color, which are translucent and have an adamantine to vitreous lustre. When fine-grained it can be bright yellow to orange, and some crystals are dark red.
Visit gemdat.org for gemological information about Crocoite.
Visit gemdat.org for gemological information about Crocoite.Unique Identifiers
Mindat ID:
1157
Long-form identifier:
mindat:1:1:1157:6
IMA Classification of Crocoite
Approved, 'Grandfathered' (first described prior to 1959)
IMA Formula:
Pb(CrO4)
Classification of Crocoite
7.FA.20
7 : SULFATES (selenates, tellurates, chromates, molybdates, wolframates)
F : Chromates
A : Without additional anions
7 : SULFATES (selenates, tellurates, chromates, molybdates, wolframates)
F : Chromates
A : Without additional anions
Dana 7th ed.:
35.3.1.1
35.3.1.1
35 : ANHYDROUS CHROMATES
3 : AXO4
35 : ANHYDROUS CHROMATES
3 : AXO4
27.2.5
27 : Sulphites, Chromates, Molybdates and Tungstates
2 : Chromates
27 : Sulphites, Chromates, Molybdates and Tungstates
2 : Chromates
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 |
|---|---|---|
| Crc | 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 Crocoite
Sub-Adamantine, Sub-Vitreous, Resinous, Waxy
Transparency:
Transparent, Translucent
Colour:
Orange, red, yellow; orange-red in transmitted light.
Streak:
Yellow-orange
Hardness:
2½ - 3 on Mohs scale
Tenacity:
Brittle
Cleavage:
Poor/Indistinct
Distinct on {110}, indistinct on {001} and {100}.
Distinct on {110}, indistinct on {001} and {100}.
Fracture:
Conchoidal
Density:
5.97 - 6.02 g/cm3 (Measured) 5.97 g/cm3 (Calculated)
Comment:
6.06 (Dundas mat.); 6.12 (artificial mat.)
Optical Data of Crocoite
Type:
Biaxial (+)
RI values:
nα = 2.29(2) nβ = 2.36(2) nγ = 2.66(2)
2V:
Measured: 57° , Calculated: 54°
Max. Birefringence:
δ = 0.370
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.
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.
Surface Relief:
Moderate
Dispersion:
very strong r > v inclined
Optical Extinction:
Y = b; Z ∧ c = 5.5°.
Pleochroism:
Weak
Comments:
X = Red-orange
Y = Red-orange
Z = Blood red
Y = Red-orange
Z = Blood red
Chemistry of Crocoite
Mindat Formula:
PbCr6+O4
Element Weights:
Elements listed:
Common Impurities:
Zn,S
Crystallography of Crocoite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Cell Parameters:
a = 7.12 Å, b = 7.421 Å, c = 6.80 Å
β = 102.41°
β = 102.41°
Ratio:
a:b:c = 0.959 : 1 : 0.916
Unit Cell V:
350.90 ų (Calculated from Unit Cell)
Z:
4
Morphology:
Crystals commonly prismatic [001] to acicular crystals with nearly square outline; elongated parallel to [101]; pseudo-octahedral at times, with {111} {111}, or acute rhombohedral with {110} {h0l}. Faces usually smooth and brilliant; {110} commonly striated [001], and the steep orthodomes rounded or distorted. Crystals are often cavernous or hollow. Massive; imperfectly columnar to granular.
Forms include:
a{100}, b{010}, c{001}, α{310}, d{210}, g{320}, m{110}, ζ{350}, f{120}, h{101}, ρ{502}, n{401}, χ{801}, k{101}, x{301}, l{401}, ε{501}, θ{601}, w{012}, z{011}, y{021}, t{111}, π{221}, ϑ{331}, s{441}, λ{112}, γ{223}, v{111}, e{11.1.1}, ψ{911}, G{812}, N{711}, η{412}, q{12.4.1}, L{2.1.10}, g{841}, Q{953}, H{435}, δ{11.10.1}, p{13.1.5}, τ{911}, r{612}, A{511}, R{18.4.1}, ξ{411}, β{312}, φ{311}, F{621}, Y{931}, B{521}, u{211}, E{328}, o{8.7.10}, M{6.10.9}, σ{352}, i{123}, μ(154}, D{265}. Also an additional couple dozen probable forms.
Forms include:
a{100}, b{010}, c{001}, α{310}, d{210}, g{320}, m{110}, ζ{350}, f{120}, h{101}, ρ{502}, n{401}, χ{801}, k{101}, x{301}, l{401}, ε{501}, θ{601}, w{012}, z{011}, y{021}, t{111}, π{221}, ϑ{331}, s{441}, λ{112}, γ{223}, v{111}, e{11.1.1}, ψ{911}, G{812}, N{711}, η{412}, q{12.4.1}, L{2.1.10}, g{841}, Q{953}, H{435}, δ{11.10.1}, p{13.1.5}, τ{911}, r{612}, A{511}, R{18.4.1}, ξ{411}, β{312}, φ{311}, F{621}, Y{931}, B{521}, u{211}, E{328}, o{8.7.10}, M{6.10.9}, σ{352}, i{123}, μ(154}, D{265}. Also an additional couple dozen probable forms.
Comment:
Space group P21/n.
Crystallographic forms of Crocoite
Crystal Atlas:
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Crocoite no.76 - Goldschmidt (1913-1926)
Crocoite no.111 - Goldschmidt (1913-1926)
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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) |
|---|---|---|---|---|---|---|---|
| 0009297 | Crocoite | Quareni S, De Pieri R (1965) A three-dimensional refinement of the structure of crocoite, PbCrO4 Acta Crystallographica 19 287-289 |  | 1965 | 0 | 293 | |
| 0019487 | Crocoite | Effenberger H, Pertlik F (1986) Four monazite type structures: comparison of SrCrO4, SrSeO4, PbCrO4 (crocoite), and PbSeO4 Zeitschrift fur Kristallographie 176 75-83 |  | 1986 | Dundas, Tasmania | 0 | 293 |
| 0014540 | Crocoite | Knight K S (2000) A high temperature structural phase transition in crocoite (PbCrO4) at 1068 K: crystal structure refinement at 1073 K and thermal expansion tensor determination at 1000 K Mineralogical Magazine 64 291-300 | | 2000 | Dundas, Tasmania | 0 | 1073 |
| 0020242 | Crocoite | Bandiello E, Errandonea D, Martinez-Garcia D, Santamaria-Perez D, Manjon F J (2012) Effects of high-pressure on the structural, vibrational, and electronic properties of monzanite-type PbCrO4 Physical Review B85 024108-10 | 2012 | Red Lead mine, Dundas, Tasmania, Australia | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Loading XRD data...
Data courtesy of RRUFF project at University of Arizona, used with permission.
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 3.277 Å | (100) |
| 3.475 Å | (80) |
| 3.030 Å | (60) |
| 4.374 Å | (50) |
| 2.254 Å | (50) |
| 4.950 Å | (30) |
| 1.846 Å | (30) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 7: Great Oxidation Event | <2.4 |
| 47e : [Vanadates, chromates, manganates] | |
| 47h : [Near-surface oxidized, dehydrated minerals] | |
| Stage 10b: Anthropogenic minerals | <10 Ka |
| 55 : Anthropogenic mine minerals |
Geological Setting:
Uncommon secondary mineral in lead deposits associated with chromium-bearing rocks.
Type Occurrence of Crocoite
Place of Conservation of Type Material:
Natural History Museum, Paris
Synonyms of Crocoite
Other Language Names for Crocoite
Catalan:Crocoita
Dutch:Crocoiet
German:Lehmannit (nach Brooke)
Bleichromat
Bleiischer Chromspath
Chrombleispath
Chromsaures Blei
Crocoisit
Kallochrom
Krokoisit
Rotbleierz
Rothes Bleierz
Bleigelb (in part)
Bleichromat
Bleiischer Chromspath
Chrombleispath
Chromsaures Blei
Crocoisit
Kallochrom
Krokoisit
Rotbleierz
Rothes Bleierz
Bleigelb (in part)
Italian:Crocoite
Japanese:紅鉛鉱
Low Saxon/Low German:Krokoit
Norwegian:Krokoitt
Portuguese:Crocoite
Russian:Крокоит
Simplified Chinese:铬铅矿
Slovak:Krokoit
Spanish:Crocoisita
Crocoita
Lehmannita
Crocoita
Lehmannita
Relationship of Crocoite to other Species
Member of:
Other Members of Monazite Supergroup:
| Cheralite | CaTh(PO4)2 | Mon. 2/m |
| Gasparite Group | REE(AsO4) | |
| Huttonite | ThSiO4 | Mon. 2/m |
| Monazite Group | REE(PO4) | |
| Rooseveltite | Bi(AsO4) | Mon. 2/m |
Common Associates
Associated Minerals Based on Photo Data:
| 289 photos of Crocoite associated with Pyromorphite | Pb5(PO4)3Cl |
| 144 photos of Crocoite associated with Vauquelinite | Pb2Cu(CrO4)(PO4)(OH) |
| 118 photos of Crocoite associated with Gibbsite | Al(OH)3 |
| 98 photos of Crocoite associated with Dundasite | PbAl2(CO3)2(OH)4 · H2O |
| 38 photos of Crocoite associated with Chrome-Cerussite | PbCO3 |
| 36 photos of Crocoite associated with Quartz | SiO2 |
| 33 photos of Crocoite associated with Cerussite | PbCO3 |
| 29 photos of Crocoite associated with Limonite | |
| 26 photos of Crocoite associated with Embreyite | Pb5(CrO4)2(PO4)2 · H2O |
| 19 photos of Crocoite associated with Goethite | Fe3+O(OH) |
Related Minerals - Strunz-mindat Grouping
| 7.FA.05 | Tarapacáite | K2(CrO4) |
| 7.FA.10 | Chromatite | CaCr6+O4 |
| 7.FA.15 | Hashemite | BaCr6+O4 |
Fluorescence of Crocoite
Not fluorescent in UV.
Other Information
Health Risks:
Chromate minerals contain the carcinogenic and mutagenic chromate ion. Always wash hands after handling. Avoid inhaling dust when handling or breaking. Never lick or ingest. Do not pour chromate-containing solutions down the drain.
Internet Links for Crocoite
mindat.org URL:
https://www.mindat.org/min-1157.html
Please feel free to link to this page.
Please feel free to link to this page.
Search Engines:
External Links:
References for Crocoite
Reference List:
Hausmann, Johann Friedrich Ludwig (1813) Handbuch der Mineralogie (1st ed.). Vandenhoeck und Ruprecht. p.1084
von Kobell, Franz (1838) Grundzüge der Mineralogie: Grundzüge der Mineralogie: zum Gebrauche bey Vorlesungen, sowie zum Selbststudium Entworfen. Johann Leonard Schrag. p.282 - as Krokoisit
Brooke, Henry J., Phillips, William (1852) An Elementary Introduction to Mineralogy (6th ed.) p.557 - as Lehmannite
Des Cloizeaux, Alfred (1882) Note sur les constantes optiques de la crocoïse. Bulletin de Minéralogie, 5 (4) 103-105 doi:10.3406/bulmi.1882.1718
Anderson, C. (1906) Mineralogical notes. No. III. Axinite, petterdite, crocoite, and datolite. Records of the Australian Museum, 6. 133-144 doi:10.3853/j.0067-1975.6.1906.998
Larsen, Esper S. (1921) The microscopic determination of the nonopaque minerals. Bulletin 679. US Geological Survey doi:10.3133/b679 p.63
Quareni, S., de Pieri, R. (1965) A three-dimensional refinement of the structure of crocoite, PbCrO4. Acta Crystallographica, 19 (2) 287-289 doi:10.1107/s0365110x65003304
Wilkins, R. W. T. (1971) The Raman spectrum of crocoite. Mineralogical Magazine, 38 (294) 249-250 doi:10.1180/minmag.1971.038.294.15
Effenberger, H., Pertlik, F. (1986) Four monazite type structures: comparison of SrCrO4, SrSeO4, PbCrO4 (crocoite), and PbSeO4. Zeitschrift für Kristallographie, 176 (1). 75-83 doi:10.1524/zkri.1986.176.1-2.75
Frost, Ray L. (2004) Raman microscopy of selected chromate minerals. Journal of Raman Spectroscopy, 35 (2). 153-158 doi:10.1002/jrs.1121
Cook, Robert B. (2007) Crocoite: Dundas, Tasmania, Australia. Rocks & Minerals, 82 (1) 50-54 doi:10.3200/rmin.82.1.50-54
Localities for Crocoite
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 | |
| |
| Palache et al. (1951) +2 other references |
| www.crocoite.com (2001) |
| Palache et al. (1951) | |
| Dana 7:II:653. +1 other reference |
| Mason (1976) +1 other reference |
| Palache et al. (1951) +1 other reference | |
| Bottrill et al. (2006) | |
| Bottrill et al. (2008) | |
| Bottrill et al. (2006) | |
| Bottrill et al. (2006) | |
| Bottrill et al. (2006) | |
| R. Bottrill +1 other reference | |
| Palache et al. (1951) +3 other references | |
| Bottrill et al. +1 other reference | |
| Bottrill et al. (2008) |
| Bottrill et al. (2008) |
| Grguric et al. (2006) |
| Rox Resources Ltd (2004) |
| Simpson et al. (1948) |
Austria | |
| Exel (1993) |
| Exel (1993) | |
Bosnia and Herzegovina | |
| Marko Bermanec Collection |
Brazil | |
| Palache et al. (1951) |
| Historical labels | |
| Eberhard Reich info taken from old ... | |
Canada | |
| Sabina (1991) |
| Sabina (1991) | |
| Sabina (1991) | |
| Sabina (1991) | |
| Sabina (1991) |
| 176-178. +2 other references |
Chile | |
| maurizio dini collection - analysed ... |
| Samples analysed by Dr. Jochen Schlüter (Hamburg University) | |
| British Museum online catalogue 2007 | |
China | |
| Guoying Chen and Wanmao Li (1991) |
DR Congo | |
| Lhoest (1992) |
France | |
| |
| Laurent et al. (1967) |
| Mari et al. (1979) |
Germany | |
| Weiß (1990) |
| EDX/XRD confirmed by Günter Blaß +1 other reference |
| Birch et al. (2000) |
Italy | |
| Prete (1995) |
| //doi.org/10.57635/MICRO.2025.23.16 |
Jordan | |
| Sokol +9 other references |
Mexico | |
| Panczner (1987) |
| Panczner (1987) | |
| Dana 7:I:518. +1 other reference | |
| Panczner (1987) | |
Mozambique | |
| Unpublished geological report. +1 other reference |
Namibia | |
| Dunn (1991) |
Philippines | |
| Rutley (1902) | |
| Palache et al. (1951) |
Poland | |
| Traube (1888) |
Romania | |
| Palache et al. (1951) +1 other reference |
| Dana 6: 914. | |
| Rădulescu |
Russia | |
| Kepezhinskas et al. (2025) |
| Local geolofist S.V.Kolesnichenko data +1 other reference |
| American Mineralogist: 73 (11-12) +2 other references |
| Cook (2007) | |
| Pavel.M. Kartashov (n.d.) | |
| Pavel.M. Kartashov (n.d.) +1 other reference |
| Lomonossow (1763) +2 other references |
| Koshkin (2014) | |
| Palache et al. (1951) |
| Sehrig (2012) |
| Dmitry A. Khanin |
| Mason (1976) | |
Slovakia | |
| Koděra (1986) |
| Koděra (1986) |
South Africa | |
| Cairncross et al. (1995) |
| De Jager (1966) |
| Cairncross et al. (1995) +1 other reference | |
| Cairncross et al. (1995) |
| Cairncross et al. (1995) |
| SAMS (South African Micromount Society) | |
Tajikistan | |
| Badalov et al. (1975) |
UK | |
| Elton et al. (2004) |
| Branston (1912) +1 other reference |
| Stanley et al. (1991) | |
| Cooper et al. (1990) |
| Cooper et al. (1990) |
| Day (1999) |
| Day (1999) |
USA | |
| Anthony et al. (1995) |
| Silliman (1881) +2 other references |
| Silliman (1881) +2 other references | |
| Anthony et al. (1995) |
| Williams (1968) +2 other references |
| Silliman (1881) +2 other references |
| Williams (1968) +2 other references | |
| Silliman (1881) +2 other references |
| Williams et al. (1963) +1 other reference |
| Williams et al. (1963) +1 other reference | |
| Palache et al. (1951) |
| Anthony et al. (1995) |
| Hanks (1884) +1 other reference |
| Palache et al. (1951) | |
| Hall (1958) +2 other references | |
| Cal Div of Mines & Geo Bulletin 189 " ... +1 other reference |
| Collected by Marek Chorazewicz. EDS ... |
| The Williamson Southern Group |
| Genth et al. (1881) |
Zimbabwe | |
| Palache et al. (1951) +1 other reference |
| Bartholomew (1990) |
Quick NavTopAbout CrocoiteUnique IdentifiersIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography Crystallographic forms Crystal StructureX-Ray Powder DiffractionGeological EnvironmentType Occurrence SynonymsOther LanguagesRelationshipsCommon AssociatesStrunz-MindatFluorescence Other InformationInternet Links References Localities Locality List
Adelaide Mine, Dundas mineral field, Zeehan mining district, West Coast municipality, Tasmania, Australia