Mikecoxite
A valid IMA mineral species
This page kindly sponsored by Michael Cox
About Mikecoxite
Formula:
[CHg4]OCl2
Colour:
Black
Lustre:
Metallic, Sub-Metallic
Specific Gravity:
8.58 (Calculated)
Crystal System:
Monoclinic
Name:
Named in honor of Michael F. Cox (b. 1958) of Soquel, California, USA. He is a founding member of the New Almaden Quicksilver County Park Association (NAQCPA) and was responsible for characterizing and remediating environmental mercury on the site. He collected the rock containing the type material. He has also contributed to the research of other mercury-bearing species and is a very active member of the Bay Area Mineralogists (California, USA).
New structure type. First natural mercuroorganic compound. First mineral with tetramercurated methane moiety within.
Found in cavities of the host rock.
Structure details:
* 3-coordinated oxygen
* strongly corrugated layers
* layer topology fits that predicted for Hofmann's base
First evidence of cleaving C-C bonds by Hg2+ in nature (at least at the time of its first description).
Found in cavities of the host rock.
Structure details:
* 3-coordinated oxygen
* strongly corrugated layers
* layer topology fits that predicted for Hofmann's base
First evidence of cleaving C-C bonds by Hg2+ in nature (at least at the time of its first description).
Unique Identifiers
Mindat ID:
55683
Long-form identifier:
mindat:1:1:55683:3
IMA Classification of Mikecoxite
Classification of Mikecoxite
3.DD.
3 : HALIDES
D : Oxyhalides, hydroxyhalides and related double halides
D : With Hg
3 : HALIDES
D : Oxyhalides, hydroxyhalides and related double halides
D : With Hg
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 |
|---|---|---|
| Mcx | 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 Mikecoxite
Metallic, Sub-Metallic
Transparency:
Opaque
Colour:
Black
Hardness Data:
Could not be measured
Comment:
Not measured but soft when manipulated with a needle.
Cleavage:
None Observed
Parting:
None Observed
Density:
8.58 g/cm3 (Calculated)
Comment:
Calculated based on the ideal formula.
Chemistry of Mikecoxite
Mindat Formula:
[CHg4]OCl2
Element Weights:
Elements listed:
Crystallography of Mikecoxite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Cell Parameters:
a = 10.164(5) Å, b = 10.490(4) Å, c = 6.547(3) Å
β = 90.037(10)°
β = 90.037(10)°
Ratio:
a:b:c = 0.969 : 1 : 0.624
Unit Cell V:
698 ų
Z:
4
Morphology:
Bladed crystals.
Twinning:
Interpenetration twins (2-fold rotation about the c-axis).
Comment:
space group is P21/n
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 5.49 Å | (34) |
| 4.65 Å | (32) |
| 2.989 Å | (81) |
| 2.884 Å | (100) |
| 2.673 Å | (79) |
| 2.300 Å | (30) |
| 2.0453 Å | (30) |
| 1.7443 Å | (40) |
Comments:
McDermitt Mine, Nevada, USA. Data from the type description.
Type Occurrence of Mikecoxite
General Appearance of Type Material:
Prismatic / bladed crystals, highly reflective, <0.1 x 0.05 mm.
Place of Conservation of Type Material:
Mineralogical collections of the Natural History Museum of Los Angeles County, 900 Exposition Boulevard, Los Angeles, CA 90007, USA, catalogue number 76196 (holotype) and 76197 (cotype).
Associated Minerals at Type Locality:
Other Language Names for Mikecoxite
Dutch:Mikecoxiet
German:Mikecoxit
Common Associates
Associations Based on Photo Data:
| 3 photos of Mikecoxite associated with Quartz | SiO2 |
| 3 photos of Mikecoxite associated with Kleinite | (Hg2N)(Cl,SO4) · nH2O |
| 2 photos of Mikecoxite associated with Eglestonite | [Hg2]2+3OCl3(OH) |
| 2 photos of Mikecoxite associated with Cinnabar | HgS |
| 2 photos of Mikecoxite associated with Terlinguacreekite | Hg2+3Cl2O2 |
| 1 photo of Mikecoxite associated with Calomel | [Hg2]2+Cl2 |
Related Minerals - Strunz-mindat Grouping
| 3.DD.05 | Eglestonite | [Hg2]2+3OCl3(OH) |
| 3.DD.05 | Kadyrelite | [Hg2]2+3OBr3(OH) |
| 3.DD.10 | Poyarkovite | [Hg2]2+3Cl2O2 |
| 3.DD.15 | Hanawaltite | [Hg2]2+3Hg2+(Cl,OH)2O3 |
| 3.DD.20 | Terlinguaite | [Hg3]4+Hg2+Cl2O2 |
| 3.DD.25 | Pinchite | Hg2+5Cl2O4 |
| 3.DD.30 | Gianellaite | [(Hg2N)2](SO4)(H2O)x |
| 3.DD.30 | Mosesite | (Hg2N)(Cl,SO4,MoO4) · H2O |
| 3.DD.35 | Kleinite | (Hg2N)(Cl,SO4) · nH2O |
| 3.DD.40 | Tedhadleyite | [Hg2]2+5Hg2+I2(Cl,Br)2O4 |
| 3.DD.45 | Vasilyevite | [Hg2]2+10I3Br2Cl[CO3]O6 |
| 3.DD.50 | Aurivilliusite | [Hg2]2+Hg2+2(I,Br,Cl)2O2 |
| 3.DD.55 | Terlinguacreekite | Hg2+3Cl2O2 |
| 3.DD.60 | Kelyanite | [Hg]2+6Sb3+BrCl2O6 |
| 3.DD.65 | Comancheite | Hg2+55N3-24(NH2,OH)4(Cl,Br)34 |
| 3.DD.70 | Gaildunningite | Hg2+3[NHg2+2]18(Cl,I,OH,Br,S)24 |
Fluorescence of Mikecoxite
Not fluorescent
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 Mikecoxite
mindat.org URL:
https://www.mindat.org/min-55683.html
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References for Mikecoxite
Reference List:
Miyawaki, Ritsuro, Hatert, Frédéric, Pasero, Marco, Mills, Stuart J. (2021) CNMNC Newsletter 64. IMA Commission on New Minerals, Nomenclature and Classification (CNMNC) Mineralogical Magazine, 86 (1) 178-182 doi:10.1180/mgm.2021.93
Cooper, Mark A., Dunning, Gail, Hawthorne, Frank C., Ma, Chi, Kampf, Anthony R., Spratt, John, Stanley, Christopher J., Christy, Andrew G. (2023) The first occurrence of the carbide anion, C4–, in an oxide mineral: Mikecoxite, ideally (CHg4)OCl2, from the McDermitt open-pit mine, Humboldt County, Nevada, U.S.A. American Mineralogist, 108 (3) 606-613 doi:10.2138/am-2022-8408
Localities for Mikecoxite
Showing 2 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.
Spain | |
| Carnegie Museum of Natural History ... |
USA (TL) | |
| Miyawaki et al. (2021) +1 other reference |
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McDermitt Mine, Opalite Mining District, Humboldt County, Nevada, USA