Mindat Logo
Home Page Log In Message Board The Mindat Directory
Register Search Pages Chat Now! (2 online) Mindat Auctions

Modderite

Formula:
(Co,Fe)As
System:OrthorhombicColour:steel grey
Hardness:4
This page provides mineralogical data about Modderite.

Classification of Modderite

IMA status:Valid - first described prior to 1959 (pre-IMA) - "Grandfathered"
Strunz 8th edition ID:2/C.19-40
Nickel-Strunz 10th (pending) edition ID:2.CC.15

2 : SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulfantimonites, sulfbismuthites, etc.)
C : Metal Sulfides, M: S = 1: 1 (and similar)
C : With Ni, Fe, Co, PGE, etc.
Hey's CIM Ref.:3.10.9

3 : Sulphides, Selenides, Tellurides, Arsenides and Bismuthides (except the arsenides, antimonides and bismuthides of Cu, Ag and Au, which are included in Section 1)
10 : Sulphides etc. of Co
mindat.org URL:http://www.mindat.org/min-2738.html
Please feel free to link to this page.

Type Occurrence of Modderite

Co-type Localities:Modderfontein Gold Mine, Johannesburg, Witwatersrand field, Gauteng Province, South Africa
Modderfontein Mine, East Rand, Witwatersrand field, Mpumalanga Province, South Africa
Year of Discovery:1923

Physical Properties of Modderite

Lustre:Metallic
Colour:steel grey
Streak:grey
Hardness (Mohs):4

Crystallography of Modderite

Crystal System:Orthorhombic
Cell Parameters:a = 3.45Å, b = 5.86Å, c = 5.29Å
Ratio:a:b:c = 0.589 : 1 : 0.903
Unit Cell Volume:V 106.95 ų (Calculated from Unit Cell)

Chemical Properties of Modderite

Formula:
(Co,Fe)As
Essential elements:As, Co
All elements listed in formula:As, Co, Fe
Common Impurities:Ni

Relationship of Modderite to other Species

Related Minerals - Nickel-Strunz Grouping):

- +
2.CC.05Achavalite
FeSe
2.CC.05Breithauptite
NiSb
2.CC.05Freboldite
CoSe
2.CC.05Kotulskite
Pd(Te,Bi)
 
1-2
2.CC.05Langisite
(Co,Ni)As
2.CC.05Nickeline
NiAs
2.CC.05Sederholmite
NiSe beta-NiSe
2.CC.05Sobolevskite
PdBi
2.CC.05Stumpflite
Pt(Sb,Bi)
2.CC.05Sudburyite
(Pd,Ni)Sb
2.CC.05Jaipurite
CoS
2.CC.05Zlatogorite
NiCuSb
 
2
2.CC.10Pyrrhotite
Fe
 
7
S
 
8
, (-4M), also given as Fe
 
1-x
S (x = 0 - 0.2)
2.CC.10Smythite
(Fe,Ni)
 
9
S
 
11
2.CC.10Troilite
FeS
2.CC.15Cherepanovite
RhAs
2.CC.15Ruthenarsenite
(Ru,Ni)As
2.CC.15Westerveldite
(Fe,Ni,Co)As
2.CC.20Millerite
NiS
2.CC.20Mäkinenite
γ-NiSe
2.CC.20UM1990-38-S:CuFeIrNiPtRh
(Ir,Pt,Ni,Fe)S
2.CC.25Mackinawite
(Fe,Ni)
 
9
S
 
8
2.CC.30Hexatestibiopanickelite
Ni(Te,Sb)
2.CC.30Vavřínite
Ni
 
2
SbTe
 
2
2.CC.35aBraggite
(Pt,Pd,Ni)S
2.CC.35bCooperite
(Pt,Pd,Ni)S
2.CC.35aVysotskite
(Pd,Ni)S
Related Minerals - Hey's Index Grouping:

- +
3.10.1Cobaltpentlandite
(Co,Ni,Fe)
 
9
S
 
8
3.10.2Linnaeite
Co
2+
 
Co
3+
2
S
 
4
3.10.3Cattierite
CoS
 
2
3.10.4Freboldite
CoSe
3.10.5Bornhardtite
Co
2+
 
Co
3+
2
Se
 
4
3.10.6Trogtalite
CoSe
 
2
3.10.7Hastite
CoSe
 
2
3.10.8Mattagamite
CoTe
 
2
3.10.10Safflorite
(Co,Fe,Ni)As
 
2
3.10.11Clinosafflorite
(Co,Fe,Ni)As
 
2
3.10.12Skutterudite
(Co,Fe,Ni)As
 
2-3
3.10.13Cobaltite
CoAsS
3.10.14Paracostibite
CoSbS
3.10.15Costibite
CoSbS
3.10.16Alloclasite
(Co
 
0.65
Fe
 
0.35
)AsS - CoAsS
3.10.17Glaucodot
(Co
 
0.50
Fe
 
0.50
)AsS
3.10.18Carrollite
Cu(Co,Ni)
 
2
S
 
4

Other Names for Modderite

Other Languages:
German:Modderit
Russian:Моддерит
Spanish:Modderita

Other Information

Health Warning:No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.

References for Modderite

Reference List:American Mineralogist (1978): 63: 600.

Internet Links for Modderite

Search Engines:
  • Look for Modderite on Google
  • Look for Modderite images on Google
    • External Links:
  • Look for Modderite on Webmineral
  • Look for Modderite on Athena Mineralogy
  • Look for Modderite on Wikipedia
  • Look for Modderite on Mineralien Atlas
  • Raman and XRD data at RRUFF project
  • American Mineralogist Crystal Structure Database
  • Search for Modderite in the Natural History Museum (London) online catalogue
  • Modderite details from Handbook of Mineralogy (PDF)
    • Mineral Dealers:
  • Buy Fine Minerals from mineralsweb.com
  • Search for - Modderite - on e-Rocks Mineral Sales & Auctions
  • SpiriferMinerals.com - high quality specimens
  • Edwards Minerals - Fine Specimens
  • Buy Minerals and Crystals from Crystalarium.com
  • DAKOTA MATRIX offers Cabinet and Rare Species from Worldwide Localities.
  • Wilensky Fine Minerals
  • Fabre Minerals - search for Modderite specimens
  • Buy fine minerals and gemstones from Pala International
  • Wendel Minerals - Auktion & Shop
  • Lapis Mineral Magazin
  • Buy from David K Joyce minerals
    • Jobs:
  • Mining & Geology Jobs

    • Page Sponsor

    Sponsorship:This page is currently not sponsored. Click here to sponsor this page.

    Localities for Modderite

    (TL) indicates type locality. ? indicates mineral may be doubtful at this locality. All other localities listed without reference should be considered as uncertain and unproven until references can be found.
    China
     
    • Xinjiang (Xinjiang-Uygur) Autonomous Region
      • Kashi (Kashgar; Qeshqer) Prefecture
        • Shache (Yarkand; Yeken) Co.
    		Xu Yong and Zhu Xinyou (2000): Acta Geologica Sinica 74(3), 540-543.
    South Africa
     
    • Gauteng Province
      • Witwatersrand field
        • Johannesburg
    		Chem.Metall.Min.Soc.S.Africa,(1924) 24, 265
    • Mpumalanga Province
      • Witwatersrand field
        • East Rand
    		Minerals of South Africa
    Mineral and/or Locality
    Google
     
    www.mindat.org Web
    Copyright © Jolyon Ralph and Ida Chau 1993-2009. Site Map. Locality, mineral & photograph data are the copyright of the individuals who submitted them.Further information contact the Site hosted & developed by Jolyon Ralph. Mindat.org is an online information resource dedicated to providing free mineralogical information to all. Mindat relies on the contributions of hundreds of members and supporters. If you would like to add information to improve the quality of our database, then click here to register. Current server date and time: 10th Nov 2009 11:43:57