Challacolloite
A valid IMA mineral species
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About Challacolloite
Formula:
KPb2Cl5
Colour:
Colourless to white
Lustre:
Adamantine, Greasy
Hardness:
2 - 3
Specific Gravity:
4.77 (Calculated)
Crystal System:
Monoclinic
Name:
Named after its type locality
Type Locality:
Isostructural with:
Unique Identifiers
Mindat ID:
27422
Long-form identifier:
mindat:1:1:27422:1
IMA Classification of Challacolloite
Approved
IMA Formula:
KPb2+2Cl5
Approval year:
2005
First published:
2005
Classification of Challacolloite
3.AA.55
3 : HALIDES
A : Simple halides, without H2O
A : M:X = 1:1, 2:3, 3:5, etc.
3 : HALIDES
A : Simple halides, without H2O
A : M:X = 1:1, 2:3, 3:5, etc.
11.4.2.1
11 : HALIDE COMPLEXES
4 : AmBX5·xH2O
11 : HALIDE COMPLEXES
4 : AmBX5·xH2O
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 |
|---|---|---|
| Chc | 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 Challacolloite
Adamantine, Greasy
Comment:
Adamantine on fresh surfaces and greasy when exposed to the atmosphere.
Colour:
Colourless to white
Streak:
White
Hardness:
2 - 3 on Mohs scale
Tenacity:
Brittle
Fracture:
Sub-Conchoidal
Density:
4.77 g/cm3 (Calculated)
Optical Data of Challacolloite
Type:
Biaxial (+)
RI values:
nα = 2.004(2) nβ = 2.01(2) nγ = 2.024(3)
2V:
Calculated: 67°
Max. Birefringence:
δ = 0.020
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:
Moderate
Chemistry of Challacolloite
Mindat Formula:
KPb2Cl5
Element Weights:
Elements listed:
Crystallography of Challacolloite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
P21/b
Cell Parameters:
a = 8.864 Å, b = 7.932 Å, c = 12.491 Å
β = 90.153°
β = 90.153°
Ratio:
a:b:c = 1.117 : 1 : 1.575
Unit Cell V:
878.2 ų
Z:
4
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) |
|---|---|---|---|---|---|---|---|
| 0019022 | Challacolloite | Mitolo D, Pinto D, Garavelli A, Bindi L, Vurro F (2009) The role of the minor substitutions in the crystal structure of natural challacolloite, KPb2Cl5, and hephaistosite, TiPb2Cl5, from Vulcano (Aeolian Archipelago, Italy) Mineralogy and Petrology 96 121-128 | 2009 | rim of La Fossa Crater, Vulcano, Aeolian Archipelago, Italy | 0 | 293 | |
| 0019134 | Challacolloite | Schluter J, Pohl D, Britvin S (2005) The new mineral challacolloite, KPb2Cl5, the natural occurrence of a technically known laser material Neues Jahrbuch fur Mineralogie, Abhandlungen 182 95-101 | 2005 | Challacollo silver mine, Iquique, Atacama desert, Chile | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 3.686 Å | (100) |
| 3.609 Å | (49) |
| 2.669 Å | (42) |
| 8.855 Å | (39) |
| 3.961 Å | (31) |
Reference:
Comments:
Format: d/Å (I/%) (hkl)
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Near-surface Processes | |
| 23 : Subaerial aqueous alteration by non-redox-sensitive fluids (see also #47) | |
| Stage 7: Great Oxidation Event | <2.4 |
| 45b : [Other oxidized fumarolic minerals] |
Geological Setting:
as a product of fumarole activity, on cavernous leucotephritic lava
Type Occurrence of Challacolloite
General Appearance of Type Material:
Thin crusts and botryoidal aggregates. Aggregates comprised of subparallel intergrowths of bent lamellae, 25 µm in width, 50 µm in length.
Place of Conservation of Type Material:
The Mineralogical Museum, University of Hamburg, Germany.
Geological Setting of Type Material:
hydrothermal phases
Associated Minerals at Type Locality:
Synonyms of Challacolloite
Other Language Names for Challacolloite
Common Associates
Associations Based on Photo Data:
| 6 photos of Challacolloite associated with Cotunnite | PbCl2 |
| 5 photos of Challacolloite associated with Uklonskovite | NaMg(SO4)F · 2H2O |
| 4 photos of Challacolloite associated with Pseudocotunnite | K2PbCl4 |
| 4 photos of Challacolloite associated with Cannizzarite | Pb48Bi56S132 |
| 4 photos of Challacolloite associated with Pseudoboleite | Pb31Cu24Cl62(OH)48 |
| 2 photos of Challacolloite associated with Steropesite | Tl3BiCl6 |
| 2 photos of Challacolloite associated with Nitratine | NaNO3 |
| 2 photos of Challacolloite associated with Bismuthinite | Bi2S3 |
| 2 photos of Challacolloite associated with Galena | PbS |
| 1 photo of Challacolloite associated with Halite | NaCl |
Related Minerals - Strunz-mindat Grouping
| 3.AA. | Brontesite | (NH4)3PbCl5 |
| 3.AA.05 | Marshite | CuI |
| 3.AA.05 | Nantokite | CuCl |
| 3.AA.05 | 'UM1999-11:I:CuS' | Cu(I,S) |
| 3.AA.05 | Miersite | (Ag,Cu)I |
| 3.AA.10 | Tocornalite | (Ag,Hg)I (?) |
| 3.AA.10 | Iodargyrite | AgI |
| 3.AA.15 | Bromargyrite | AgBr |
| 3.AA.15 | Chlorargyrite | AgCl |
| 3.AA.20 | Sylvite | KCl |
| 3.AA.20 | Halite | NaCl |
| 3.AA.20 | Villiaumite | NaF |
| 3.AA.20 | Carobbiite | KF |
| 3.AA.20 | Griceite | LiF |
| 3.AA.25 | 'UM1998-03-Cl:Tl' | TlCl |
| 3.AA.25 | Nataliyamalikite | TlI |
| 3.AA.25 | Lafossaite | Tl(Cl,Br) |
| 3.AA.25 | Salammoniac | NH4Cl |
| 3.AA.30 | Calomel | [Hg2]2+Cl2 |
| 3.AA.30 | Moschelite | [Hg2]2+I2 |
| 3.AA.30 | Kuzminite | HgBr |
| 3.AA.35 | Neighborite | NaMgF3 |
| 3.AA.35 | Parascandolaite | KMgF3 |
| 3.AA.40 | Javorieite | KFeCl3 |
| 3.AA.40 | Chlorocalcite | KCaCl3 |
| 3.AA.45 | Kolarite | PbTeCl2 |
| 3.AA.50 | Radhakrishnaite | PbTe3(Cl,S)2 |
| 3.AA.60 | Hephaistosite | TlPb2Cl5 |
| 3.AA.90 | Pseudocotunnite | K2PbCl4 |
Radioactivity
Radioactivity:
| Element | % Content | Activity (Bq/kg) | Radiation Type |
|---|---|---|---|
| Uranium (U) | 0.0000% | 0 | α, β, γ |
| Thorium (Th) | 0.0000% | 0 | α, β, γ |
| Potassium (K) | 6.1986% | 1,922 | β, γ |
For comparison:
- Banana: ~15 Bq per fruit
- Granite: 1,000–3,000 Bq/kg
- EU exemption limit: 10,000 Bq/kg
Note: Risk is shown relative to daily recommended maximum exposure to non-background radiation of 1000 µSv/year. Note that natural background radiation averages around 2400 µSv/year so in reality these risks are probably extremely overstated! With infrequent handling and safe storage natural radioactive minerals do not usually pose much risk.
Interactive Simulator:
Note: The mass selector refers to the mass of radioactive mineral present, not the full specimen, also be aware that the matrix may also be radioactive, possibly more radioactive than this mineral!
Activity: –
| Distance | Dose rate | Risk |
|---|---|---|
| 1 cm | ||
| 10 cm | ||
| 1 m |
The external dose rate (D) from a radioactive mineral is estimated by summing the gamma radiation contributions from its Uranium, Thorium, and Potassium content, disregarding daughter-product which may have a significant effect in some cases (eg 'pitchblende'). This involves multiplying the activity (A, in Bq) of each element by its specific gamma ray constant (Γ), which accounts for its unique gamma emissions. The total unshielded dose at 1 cm is then scaled by the square of the distance (r, in cm) and multiplied by a shielding factor (μshield). This calculation provides a 'worst-case' or 'maximum risk' estimate because it assumes the sample is a point source and entirely neglects any self-shielding where radiation is absorbed within the mineral itself, meaning actual doses will typically be lower. The resulting dose rate (D) is expressed in microsieverts per hour (μSv/h).
D = ((AU × ΓU) + (ATh × ΓTh) + (AK × ΓK)) / r2 × μshield
Fluorescence of Challacolloite
Not fluorescent
Other Information
Notes:
Dissolves in H2O and 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 Challacolloite
mindat.org URL:
https://www.mindat.org/min-27422.html
Please feel free to link to this page.
Please feel free to link to this page.
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References for Challacolloite
Reference List:
Schlüter, Jochen, Pohl, Dieter, Britvin, Sergey (2005) The new mineral challacolloite, KPb2Cl5, the natural occurrence of a technically known laser material. Neues Jahrbuch für Mineralogie - Abhandlungen, 182 (1) 95-101 doi:10.1127/0077-7757/2005/0033
Piilonen, P. C.; Rowe, R.; Ercit, T.S.; Locock, A.J. (2006) New Mineral Names. American Mineralogist, 91 (8). 1452-1457 doi:10.2138/am.2006.470
Mitolo, D., Pinto, D., Garavelli, A., Bindi, L., Vurro, F. (2009) The role of the minor substitutions in the crystal structure of natural challacolloite, KPb2Cl5, and hephaistosite, TlPb2Cl5, from Vulcano (Aeolian Archipelago, Italy) Mineralogy and Petrology, 96 (1) 121-128 doi:10.1007/s00710-008-0041-2
Localities for Challacolloite
Showing 12 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.
Chile | |
| Brugger et al. (2012) |
| J. Schlüter at al.: N. Jb. Min. Abh. 182 (1) |
Italy | |
| Schlüter et al. (2005) +1 other reference |
| Kasatkin et al. (2023) |
| Schlüter et al. (2005) | |
| Pellino et al. (2025) | |
| Mitolo et al. (2009) |
Japan | |
| Africano et al. (2002) |
| Africano et al. (2002) | |
Russia | |
| Pekov et al. (2015) |
| Pekov et al. (2015) | |
| • Tkachenko et al. (1999) |
Quick NavTopAbout ChallacolloiteUnique IdentifiersIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography Crystal StructureX-Ray Powder DiffractionGeological EnvironmentType Occurrence SynonymsOther LanguagesCommon AssociatesStrunz-MindatRadioactivityFluorescence Other InformationInternet Links References Localities Locality List
La Fossa crater, Vulcano Island, Lipari, Eolie Islands, Metropolitan City of Messina, Sicily, Italy