Erdite
A valid IMA mineral species
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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.
This page provides mineralogical data about Erdite.
Unique Identifiers
Mindat ID:
1394
Long-form identifier:
mindat:1:1:1394:5
GUID
(UUID V4):
(UUID V4):
1ca24dc2-0ec0-4812-8eb8-4069a6b066f1
IMA Classification of Erdite
Classification of Erdite
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
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 |
---|---|---|
Erd | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Pronunciation of Erdite
Pronunciation:
Play | Recorded by | Country |
---|---|---|
Jolyon 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
Optical Data of Erdite
Anisotropism:
Strong.
Reflectivity:
Wavelength | R1 | R2 |
---|---|---|
400nm | 10.2% | 23.8% |
420nm | 9.8% | 28.8% |
440nm | 10.1% | 27.3% |
460nm | 10.9% | 20.8% |
480nm | 11.3% | 15.6% |
500nm | 11.3% | 16.6% |
520nm | 11.0% | 23.3% |
540nm | 10.6% | 25.7% |
560nm | 10.3% | 25.7% |
580nm | 10.0% | 31.6% |
600nm | 9.8% | 36.6% |
620nm | 9.7% | 43.1% |
640nm | 9.8% | 46.9% |
660nm | 10.0% | 44.3% |
680nm | 10.6% | 39.3% |
700nm | 11.0% | 35.3% |
Graph shows reflectance levels at different wavelengths (in nm). Top of box is 100%. Peak reflectance is 46.9%.
R1 shown in black, R2 shown in red
Pleochroism:
Strong
Comments:
Extreme. Brilliant reddish-orange through greenish grays and pinkish grays to dark gray with barely perceptible bluish or greenish tint.
Chemistry of Erdite
Mindat 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 1 mm long.
Crystal Structure
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2x2x2 | 3x3x3 | 4x4x4
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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) |
---|---|---|---|---|---|---|---|
0000785 | Erdite | Konnert J A, Evans H T (1980) The crystal structure of erdite, NaFeS2*2H2O American Mineralogist 65 516-521 | 1980 | Coyote Peak, Humboldt County, California, USA | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
d-spacing | Intensity |
---|---|
6.935 Å | (100) |
5.342 Å | (71) |
4.556 Å | (41) |
3.467 Å | (28) |
2.310 Å | (23) |
2.902 Å | (15) |
3.317 Å | (12) |
Comments:
Coyote Peak, California, USA.
Geological Environment
Paragenetic Mode(s):
Paragenetic Mode | Earliest Age (Ga) |
---|---|
Stage 4a: Earth’s earliest continental crust | >4.4-3.0 |
19 : Granitic intrusive rocks | |
Stage 7: Great Oxidation Event | <2.4 |
47a : [Near-surface hydration of prior minerals] |
Geological Setting:
Pegmatites in nepheline syenite
Type Occurrence of Erdite
General Appearance of Type Material:
Copper-red granular masses of impure erdite reach dimensions of several millimeters. The largest clean single crystals measure 0.5 x 1 mm.
Place of Conservation of Type Material:
National Museum of Natural History, Washington, D.C., USA.
Geological Setting of Type Material:
In mafic, alkalic diatreme. Very young rock (29 m.y.)
Associated Minerals at Type Locality:
Synonyms of Erdite
Other Language Names for Erdite
Common Associates
Associated Minerals Based on Photo Data:
17 photos of Erdite associated with Martinite | (Na,◻,Ca)12Ca4(Si,S,B)14B2O38(OH,Cl)2F2 · 4H2O |
7 photos of Erdite associated with Hackmanite | Na8Al6Si6O24(Cl2,S) |
5 photos of Erdite associated with Phlogopite | KMg3(AlSi3O10)(OH)2 |
5 photos of Erdite associated with Nepheline | Na3K(Al4Si4O16) |
5 photos of Erdite associated with Aegirine | NaFe3+Si2O6 |
3 photos of Erdite associated with Schorlomite | Ca3Ti2(SiO4)(Fe3+O4)2 |
2 photos of Erdite associated with Coyoteite | NaFe3S5 · 2H2O |
2 photos of Erdite associated with Rasvumite | KFe2S3 |
1 photo of Erdite associated with Sidorenkite | Na3Mn2+(CO3)(PO4) |
1 photo of Erdite associated with Sazhinite-(Ce) | Na2CeSi6O14 · 6H2O |
Related Minerals - Strunz-mindat Grouping
2.FD. | Ferrovalleriite | 2(Fe,Cu)S · 1.5Fe(OH)2 |
2.FD.05 | Kermesite | Sb2S2O |
2.FD.10 | Viaeneite | (Fe,Pb)4S8O |
2.FD.25 | Coyoteite | NaFe3S5 · 2H2O |
2.FD.30 | Haapalaite | (Fe2+,Ni)2(Mg,Fe2+)1.61S2(OH)3.22 |
2.FD.30 | Valleriite | (Fe2+,Cu)4(Mg,Al)3S4(OH,O)6 |
2.FD.30 | Yushkinite | (Mg,Al)V4+S2(OH)2 |
2.FD.30 | Ekplexite | (Nb,Mo,W)S2 · (Mg1-xAlx)(OH)2+x |
2.FD.35 | Tochilinite | Fe2+5-6(Mg,Fe2+)5S6(OH)10 |
2.FD.35 | Ferrotochilinite | Fe2+6(Fe2+,Mg)5S6(OH)10 |
2.FD.35 | Kaskasite | (Mo,Nb)S2 · (Mg1-xAlx)(OH)2+x |
2.FD.35 | Manganokaskasite | (Mo,Nb)S2 · (Mn1-xAlx)(OH)2+x |
2.FD.40 | Wilhelmramsayite | Cu3FeS3 · 2H2O |
2.FD.45 | Vyalsovite | FeCaAlS(OH)5 |
2.FD.50 | Bazhenovite | Ca8S2(S3)(S2O3)(OH)12 · 20H2O |
2.FD.55 | UM2004-56-OS:BiCuPb | PbCu4Bi4S2(O,OH,H2O)16 (?) |
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.
Internet Links for Erdite
mindat.org URL:
https://www.mindat.org/min-1394.html
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References for Erdite
Localities for Erdite
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).
Struck out - Mineral was erroneously reported from this locality.
Faded * - Never found at this locality but inferred to have existed at some point in the past (e.g. from pseudomorphs).
All localities listed without proper references should be considered as questionable.
All localities listed without proper references should be considered as questionable.
Canada | |
| Horváth et al. (1990) +1 other reference |
| Horváth et al. (1998) |
Horváth et al. (1998) | |
Poland | |
| Cu +2 other references |
Russia | |
| [World of Stones 95:5-6 |
USA (TL) | |
| Van Nostrand Reinholt Press: 67 +4 other references |
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Coyote Peak, Coastal Range, Humboldt County, California, USA