Erdite
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About Erdite
Formula:
NaFeS2 · 2H2O
Colour:
Copper-red
Lustre:
Metallic
Hardness:
2
Specific Gravity:
2.30
Crystal System:
Monoclinic
Name:
Named by G.K. Czamanske, B.F. Leonard, J.R. Clark in 1980 in honor of Richard Clarkson "Dick" Erd (29 February 1924, Lexington, Kentucky, USA - 20 May 2008, Springdale, Arkansas, USA), mineralogist with the US Geological Survey. He had previously synthesized the substance in 1956.
Type Locality:
This page provides mineralogical data about Erdite.
Classification of Erdite
Approved
Approval Year:
1978
First Published:
1980
2/F.09-10
2.FD.20
2 : SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulfantimonites, sulfbismuthites, etc.)
F : Sulfides of arsenic, alkalies; sulfides with halide, oxide, hydroxide, H2O
D : With O, OH, H2O
2 : SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulfantimonites, sulfbismuthites, etc.)
F : Sulfides of arsenic, alkalies; sulfides with halide, oxide, hydroxide, H2O
D : With O, OH, H2O
Dana 7th ed.:
2.14.5.1
2.14.5.1
2 : SULFIDES
14 : Hydroxysulfides and Hydrated Sulfides
2 : SULFIDES
14 : Hydroxysulfides and Hydrated Sulfides
3.0.1
3 : Sulphides, Selenides, Tellurides, Arsenides and Bismuthides (except the arsenides, antimonides and bismuthides of Cu, Ag and Au, which are included in Section 1)
0 : Sulphides etc. of the alkalis
3 : Sulphides, Selenides, Tellurides, Arsenides and Bismuthides (except the arsenides, antimonides and bismuthides of Cu, Ag and Au, which are included in Section 1)
0 : Sulphides etc. of the alkalis
Pronounciation of Erdite
Pronounciation:
Play | Recorded by | Country |
---|---|---|
Jolyon & Katya Ralph | United Kingdom |
Physical Properties of Erdite
Metallic
Transparency:
Opaque
Colour:
Copper-red
Comment:
Tarnishes quickly
Streak:
Black
Hardness:
2 on Mohs scale
Hardness:
VHN15=22 - 67 kg/mm2 - Vickers
Cleavage:
Distinct/Good
{110} Good
{110} Good
Density:
2.30 g/cm3 (Measured) 2.216 g/cm3 (Calculated)
Comment:
Measured contaminated with magnetite
Chemical Properties of Erdite
Formula:
NaFeS2 · 2H2O
Common Impurities:
K
Crystallography of Erdite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
B2/b
Setting:
C2/c
Cell Parameters:
a = 10.693 Å, b = 9.115 Å, c = 5.507 Å
β = 92.17°
β = 92.17°
Ratio:
a:b:c = 1.173 : 1 : 0.604
Unit Cell V:
536.36 ų (Calculated from Unit Cell)
Z:
4
Morphology:
Minute fibers, fine bladed crystals to 1mm long.
Type Occurrence of Erdite
Place of Conservation of Type Material:
Smithsonian
Geological Setting of Type Material:
In mafic, alkalic diatreme
Associated Minerals at Type Locality:
Synonyms of Erdite
Other Language Names for Erdite
Common Associates
Associated Minerals Based on Photo Data:
Related Minerals - Nickel-Strunz Grouping
2.FD. | UKI-2004-(OS:BiCuPb) | PbCu4Bi4S2O16 (?) | Tet. |
2.FD.05 | Kermesite | Sb2S2O | Tric. 1 : P1 |
2.FD.10 | Viaeneite | (Fe,Pb)4S8O | Mon. |
2.FD.25 | Coyoteite | NaFe3S5 · 2H2O | Tric. |
2.FD.30 | Haapalaite | (Fe2+,Ni)2(Mg,Fe2+)1.61S2(OH)3.22 | Hex. |
2.FD.30 | Valleriite | (Fe2+,Cu)4(Mg,Al)3S4(OH,O)6 | Hex. |
2.FD.30 | Yushkinite | (Mg,Al)V4+S2(OH)2 | Hex. |
2.FD.35 | Tochilinite | Fe2+5-6(Mg,Fe2+)5S6(OH)10 | |
2.FD.40 | Wilhelmramsayite | Cu3FeS3·2H2O | Orth. mmm (2/m 2/m 2/m) : Pmmm |
2.FD.45 | Vyalsovite | FeCaAlS(OH)5 | Orth. |
2.FD.50 | Bazhenovite | Ca8S2(S3)(S2O3)(OH)12 · 20H2O | Mon. 2/m : P21/b |
Related Minerals - Hey's Chemical Index of Minerals Grouping
3.0.2 | Coyoteite | NaFe3S5 · 2H2O | Tric. |
3.0.3 | Chvilevaite | Na(Cu,Fe,Zn)2S4 | Trig. 3m : R3m |
3.0.4 | Rasvumite | KFe2S3 | Orth. mmm (2/m 2/m 2/m) : Cmcm |
3.0.5 | Bartonite | K6Fe20S26S | Tet. 4/mmm (4/m 2/m 2/m) : I4/mmm |
3.0.6 | Murunskite | K2(Cu,Fe)4S4 | Tet. |
Other Information
Thermal Behaviour:
When heated in a closed tube, it gives off water, sulfur and eventually turns black and strongly magnetic.
Notes:
Easily soluble in cold dilute acids with effervescence of H2S.
Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.
References for Erdite
Reference List:
Sort by Year (asc) | by Year (desc) | by Author (A-Z) | by Author (Z-A)
Czamanske, G.K., Leonard, B.F., Clark, J.R. (1980) Erdite, a new hydrated sodium iron sulfide mineral. American Mineralogist: 65: 509-515.
Konnert, J.A., Evans, H.T. (1980) The crystal structure of erdite, NaFeS2•2H2O. American Mineralogist: 65: 516-521.
Internet Links for Erdite
mindat.org URL:
https://www.mindat.org/min-1394.html
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Localities for Erdite
Locality List




All localities listed without proper references should be considered as questionable.
Canada | |
| Horváth, L and Gault, R.A. (1990), The mineralogy of Mont Saint-Hilaire Quebec. Mineralogical Record: 21: 284-359.; Pekov, I. et al (2003): New Data on Minerals: 38: 20-33. |
| HORVÁTH, L., PFENNINGER HORVÁTH, E., GAULT, R.A., and TARASSOFF, P. (1998) Mineralogy of the Saint Amable sill, Varennes and Saint Amable, Québec, Canada. Mineralogical Record, 29, 83 118. |
Horváth, L., Pfenninger-Horváth, E., Gault, R. A., & Tarassoff, P. (1998): Mineralogy of the Saint-Amable Sill, Varennes and Saint-Amable, Québec. Mineralogical Record, 29: 83-118. | |
Russia | |
| [World of Stones 95:5-6, p64] |
USA (TL) | |
| Czamanske, G.K., B.F. Leonard & J.R. Clark (1980), Erdite, a new hydrated sodium iron sulfide mineral: American Mineralogist: 65: 506-515; Konnert, J.A. and Evans, H.T. (1980) The crystal structure of erdite, NaFeS2 •2H2O. American Mineralogist: 65: 516-521; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 67, 367; American Mineralogist: (1983) 68: 245-254. |
Coyote Peak, Coastal Range, Humboldt Co., California, USA