Kempite
A valid IMA mineral species - grandfathered
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About Kempite
James Furman Kemp
Formula:
Mn2+2(OH)3Cl
Colour:
Emerald-green, brownish-orange
Hardness:
3½
Specific Gravity:
~2.94
Crystal System:
Orthorhombic
Member of:
Name:
Named by Austin F. Rogers in 1924 in honor of James Furman Kemp (14 August 1859, New York City, New York, USA - 17 November 1926, New York City, New York, USA), mining geologist, and Professor of Geology, Columbia University.
Unique Identifiers
Mindat ID:
2183
Long-form identifier:
mindat:1:1:2183:4
IMA Classification of Kempite
Approved, 'Grandfathered' (first described prior to 1959)
IMA Formula:
Mn2+2Cl(OH)3
First published:
1924
Classification of Kempite
3.DA.10a
3 : HALIDES
D : Oxyhalides, hydroxyhalides and related double halides
A : With Cu, etc., without Pb
3 : HALIDES
D : Oxyhalides, hydroxyhalides and related double halides
A : With Cu, etc., without Pb
10.1.4.1
10 : OXYHALIDES AND HYDROXYHALIDES
1 : A2(O,OH)3Xq
10 : OXYHALIDES AND HYDROXYHALIDES
1 : A2(O,OH)3Xq
8.10.2
8 : Halides - Fluorides, Chlorides, Bromides and Iodides; also Fluoborates and Fluosilicates
10 : Halides of Mn
8 : Halides - Fluorides, Chlorides, Bromides and Iodides; also Fluoborates and Fluosilicates
10 : Halides 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 for Standard |
|---|---|---|
| Kp | 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 Kempite
Transparency:
Translucent
Colour:
Emerald-green, brownish-orange
Comment:
green in transmitted light; semitransparent
Hardness:
3½ on Mohs scale
Comment:
ca. 3.5
Density:
~2.94 g/cm3 (Measured) 2.96 g/cm3 (Calculated)
Optical Data of Kempite
Type:
Biaxial (-)
RI values:
nα = 1.684 nβ = 1.695 nγ = 1.698
2V:
Calculated: 54°
Max. Birefringence:
δ = 0.014
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
Dispersion:
r > v
Comments:
2V: 54o52'
Chemistry of Kempite
Mindat Formula:
Mn2+2(OH)3Cl
Element Weights:
Elements listed:
Crystallography of Kempite
Crystal System:
Orthorhombic
Class (H-M):
mmm(2/m2/m2/m) - Dipyramidal
Space Group:
Pnma
Setting:
Pnma
Cell Parameters:
a = 6.49 Å, b = 9.52 Å, c = 7.12 Å
Ratio:
a:b:c = 0.682 : 1 : 0.748
Unit Cell V:
439.91 ų (Calculated from Unit Cell)
Z:
4
Morphology:
Crystals prismatic [001]; {110}, {011}, and {121} forms observed; {100} and {010} are usually absent or inconspicuous.
Comment:
Cu2Cl(OH)3 type
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 2.386 Å | (100) |
| 5.70 Å | (80) |
| 5.36 Å | (70) |
| 2.965 Å | (70) |
| 1.690 Å | (35) |
| 2.895 Å | (20) |
| 2.842 Å | (20) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| High-? alteration and/or metamorphism | |
| 32 : Ba/Mn/Pb/Zn deposits, including metamorphic deposits | |
| Stage 7: Great Oxidation Event | <2.4 |
| 47a : [Near-surface hydration of prior minerals] | |
| 47e : [Vanadates, chromates, manganates] | |
| 47g : [Halogen-bearing surface weathering minerals] |
Type Occurrence of Kempite
General Appearance of Type Material:
fine, powdery, emerald-green to brownish-orange encrustations on manganese-stained rock, coating fracture faces and veins in altered serpentinized rock and chert breccia
Place of Conservation of Type Material:
National Museum of Natural History, Washington, D.C., USA (registration no. R1352)
Geological Setting of Type Material:
Erratic boulder
Associated Minerals at Type Locality:
Other Language Names for Kempite
Relationship of Kempite to other Species
Member of:
Other Members of Atacamite Group:
| Atacamite | Cu2(OH)3Cl | Orth. mmm(2/m2/m2/m) : Pnma |
| Botallackite | Cu2(OH)3Cl | Mon. 2/m : P21/m |
| Clinoatacamite | Cu2(OH)3Cl | Mon. 2/m |
| Gillardite | Cu3Ni(OH)6Cl2 | Trig. 3m(32/m) : R3m |
| Haydeeite | Cu3Mg(OH)6Cl2 | Trig. 3m(32/m) : P3m1 |
| Herbertsmithite | Cu3Zn(OH)6Cl2 | Trig. 3m(32/m) : R3m |
| Hibbingite | Fe2+2(OH)3Cl | Orth. mmm(2/m2/m2/m) : Pnma |
| Iyoite | MnCuCl(OH)3 | Mon. 2/m : P21/m |
| Kapellasite | Cu3Zn(OH)6Cl2 | Trig. 3m(32/m) : P3m1 |
| Kuliginite | Fe3Mg(OH)6Cl2 | Trig. 3 : R3 |
| Leverettite | Cu3Co(OH)6Cl2 | Trig. 3 : R3 |
| Misakiite | Cu3Mn(OH)6Cl2 | Trig. 3m(32/m) : P3m1 |
| Paratacamite | Cu3(Cu,Zn)(OH)6Cl2 | Trig. 3 : R3 |
| Paratacamite-(Mg) | Cu3(Mg,Cu)(OH)6Cl2 | Trig. 3 : R3 |
| Paratacamite-(Ni) | Cu3(Ni,Cu)(OH)6Cl2 | Trig. 3 : R3 |
| Tondiite | Cu3Mg(OH)6Cl2 | Trig. 3m(32/m) : R3m |
| 'Unnamed (Cu-Zn Chloride Hydroxide)' | CuZnCl(OH)3 | Mon. 2/m : P21/m |
Forms a series with:
Common Associates
Associations Based on Photo Data:
| 5 photos of Kempite associated with Baryte | BaSO4 |
| 1 photo of Kempite associated with Hausmannite | Mn2+Mn3+2O4 |
| 1 photo of Kempite associated with 'Psilomelane' |
Related Minerals - Strunz-mindat Grouping
| 3.DA. | Parahibbingite | Fe2(OH)3Cl |
| 3.DA. | Centennialite | CaCu3Cl2(OH)6 · nH2O (n ~ 0.7) |
| 3.DA. | Bounahasite | Cu+Cu2+2(OH)3Cl2 |
| 3.DA. | Muonionalustaite | Ni3(OH)4Cl2 · 4H2O |
| 3.DA.05 | Melanothallite | Cu2Cl2O |
| 3.DA.10c | Haydeeite | Cu3Mg(OH)6Cl2 |
| 3.DA.10b | Clinoatacamite | Cu2(OH)3Cl |
| 3.DA.10c | Paratacamite | Cu3(Cu,Zn)(OH)6Cl2 |
| 3.DA.10c | Kapellasite | Cu3Zn(OH)6Cl2 |
| 3.DA.10c | Leverettite | Cu3Co(OH)6Cl2 |
| 3.DA.10a | Hibbingite | Fe2+2(OH)3Cl |
| 3.DA.10c | Paratacamite-(Ni) | Cu3(Ni,Cu)(OH)6Cl2 |
| 3.DA.10c | Tondiite | Cu3Mg(OH)6Cl2 |
| 3.DA.10a | Atacamite | Cu2(OH)3Cl |
| 3.DA.10b | Belloite | Cu(OH)Cl |
| 3.DA.10c | Misakiite | Cu3Mn(OH)6Cl2 |
| 3.DA.10b | Iyoite | MnCuCl(OH)3 |
| 3.DA.10c | Kuliginite | Fe3Mg(OH)6Cl2 |
| 3.DA.10c | Gillardite | Cu3Ni(OH)6Cl2 |
| 3.DA.10b | 'Unnamed (Cu-Zn Chloride Hydroxide)' | CuZnCl(OH)3 |
| 3.DA.10b | Botallackite | Cu2(OH)3Cl |
| 3.DA.10c | Herbertsmithite | Cu3Zn(OH)6Cl2 |
| 3.DA.15 | Claringbullite | Cu4ClF(OH)6 |
| 3.DA.15 | Barlowite | Cu4BrF(OH)6 |
| 3.DA.20 | Simonkolleite | Zn5Cl2(OH)8 · H2O |
| 3.DA.25 | Buttgenbachite | Cu19(NO3)2(OH)32Cl4 · 2H2O |
| 3.DA.25 | Connellite | Cu19(SO4)(OH)32Cl4 · 3H2O |
| 3.DA.30 | Abhurite | Sn21Cl16(OH)14O6 |
| 3.DA.35 | Ponomarevite | K4Cu4Cl10O |
| 3.DA.40 | Calumetite | CaCu4(OH)8Cl2 · 3.5H2O |
| 3.DA.40 | Anthonyite | Cu(OH,Cl)2 · 3H2O |
| 3.DA.45 | Khaidarkanite | Cu4Al3(OH)14F3 · 2H2O |
| 3.DA.50 | Bobkingite | Cu5Cl2(OH)8 · 2H2O |
| 3.DA.55 | Avdoninite | K2Cu5(OH)4Cl8 · H2O |
| 3.DA.60 | Droninoite | Ni6Fe3+2(OH)16Cl2 · 4H2O |
| 3.DA.70 | Chrysothallite | K6Cu6Tl3+Cl17(OH)4 · H2O |
| 3.DA.70 | Dioskouriite | CaCu4Cl6(OH)4 · 4H2O |
| 3.DA.75 | Feodosiyite | Cu11Mg2Cl18(OH)8 · 16H2O |
| 3.DA.80 | Romanorlovite | K8Cu6Cl17(OH)3 |
Other Information
Notes:
is insoluble in cold water but decomposes slowly
in dilute acids, releasing chloride ions and leaving a
manganese oxide residue.
in dilute acids, releasing chloride ions and leaving a
manganese oxide residue.
Special Storage/
Display Requirements:
Display Requirements:
hygroscopic
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 Kempite
mindat.org URL:
https://www.mindat.org/min-2183.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 Kempite
Reference List:
Saini-Eidukat, Bernhardt, Rudashevsky, Nikolai S., Polozov, Alexander G. (1998) Evidence for hibbingite–kempite solid solution. Mineralogical Magazine, 62 (2) 251-255 doi:10.1180/002646198547602
Localities for Kempite
Showing 6 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.
Russia | |
| Mazurov et al. (2007) |
| v. 42 +2 other references |
| Pavel M. Kartashov analytical data of ... | |
Slovakia | |
| Radvanec M. and Gonda S. (2020) |
USA (TL) | |
| Rogers (1924) +7 other references |
| Carlson et al. (2014) |
Quick NavTopAbout KempiteUnique IdentifiersIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography X-Ray Powder DiffractionGeological EnvironmentType Occurrence Other LanguagesRelationshipsCommon AssociatesStrunz-MindatOther InformationInternet Links References Localities Locality List
Mn occurrence, East Foothills, Black Wonder Mining District, Santa Clara County, California, USA