Help mindat.org|Log In|Register|
Home PageMindat NewsThe Mindat ManualHistory of MindatCopyright StatusManagement TeamContact UsAdvertise on Mindat
Donate to MindatSponsor a PageSponsored PagesTop Available PagesMindat AdvertisersAdvertise on MindatThe Mindat Store
Minerals by PropertiesMinerals by ChemistryRandom MineralSearch by minIDLocalities Near MeSearch GlossaryMore Search Options
Search For:
Mineral Name:
Locality Name:
Keyword(s):
 
The Mindat ManualAdd a New PhotoRate PhotosLocality Edit ReportAdd Glossary Item
StatisticsMember ListBooks & MagazinesMineral Shows & EventsThe Mindat DirectoryHow to Link to MindatDevice Settings
Photo SearchPhoto GalleriesNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day Gallery

Stilpnomelane

This page is currently not sponsored. Click here to sponsor this page.
Formula:
(K,Ca,Na)(Fe2+,Mg,Al,Fe3+)8(Si,Al)12(O,OH)36 · nH2O
System:
Triclinic
Colour:
Red, brown, black, dark ...
Hardness:
3 - 4
Name:
Named in 1827 by Ernst Friedrich Glocke from Greek στιλπνοζ "stilpnos" ("shining"), and μελανοζ "melanos" ("black"), alluding to its appearance.
May be confused with biotite and other brownish mica.

Classification of Stilpnomelane

Valid - first described prior to 1959 (pre-IMA) - "Grandfathered"
9.EG.40

9 : SILICATES (Germanates)
E : Phyllosilicates
G : Double nets with 6-membered and larger rings
74.1.1.1

74 : PHYLLOSILICATES Modulated Layers
1 : Modulated Layers with joined islands
16.20.9

16 : Silicates Containing Aluminum and other Metals
20 : Aluminosilicates of Fe, Mg and alkalis
mindat.org URL:
http://www.mindat.org/min-3789.html
Please feel free to link to this page.

Type Occurrence of Stilpnomelane

Year of Discovery:
1827

Occurrences of Stilpnomelane

Geological Setting:
Banded iron formations, blueschist and greenschist facies of metamorphic rocks, metamorphosed massive sulphide deposits.

Physical Properties of Stilpnomelane

Sub-Vitreous, Pearly, Sub-Metallic
Diaphaneity (Transparency):
Translucent
Comment:
Pearly to vitreous on cleavage
Colour:
Red, brown, black, dark green, dark reddish brown, golden brown
Streak:
White, grey
Hardness (Mohs):
3 - 4
Cleavage:
Perfect
Perfect on {001}
imperfect {010}
Density:
2.59 - 2.96 g/cm3 (Measured)    2.667 g/cm3 (Calculated)

Crystallography of Stilpnomelane

Crystal System:
Triclinic
Class (H-M):
1 - Pinacoidal
Space Group:
P1
Cell Parameters:
a = 21.72Å, b = 21.72Å, c = 17.4Å
α = 124.14°, β = 95.86°, γ = 120°
Ratio:
a:b:c = 1 : 1 : 0.801
Morphology:
Plates or scales, plumose or radiating groups

Optical Data of Stilpnomelane

Type:
Biaxial (-)
RI values:
nα = 1.543 - 1.634 nβ = 1.576 - 1.745 nγ = 1.576 - 1.745
Max Birefringence:
δ = 0.033 - 0.111
Image shows birefringence interference colour range (at 30µm thickness) and does not take into account mineral colouration.
Surface Relief:
Moderate
Dispersion:
none
Pleochroism:
Visible
Comments:
X- bright golden yellow to pale yellow
Y= Z= deep reddish brown, to deep green to nearly black

Chemical Properties of Stilpnomelane

Formula:
(K,Ca,Na)(Fe2+,Mg,Al,Fe3+)8(Si,Al)12(O,OH)36 · nH2O
Essential elements:
All elements listed in formula:
Common Impurities:
Ti,Mn,Ca,Na,K,H2O

Relationship of Stilpnomelane to other Species

Other Members of Group:
ChalcoditeK(Fe3+,Mg,Fe2+)8(Si,Al)12(O,OH)27
Franklinphilite(K,Na)4(Mn,Zn,Mg,Fe)48(Si,Al)72(O,OH)216 · 6H2O
LennilenapeiteK6-7(Mg,Mn,Fe,Zn)48(Si,Al)72(O,OH)216 · 16H2O
Parsettensite(K,Na,Ca)7.5(Mn,Mg)49Si72O168(OH)50 · nH2O
9.EG.05CymriteBaAl2Si2(O,OH)8 · H2O
9.EG.10Naujakasite(Na,K)6(Fe2+,Mn2+,Ca)(Al,Fe)4Si8O26
9.EG.10ManganonaujakasiteNa6(Mn2+,Fe2+)Al4Si8O26
9.EG.15DmisteinbergiteCaAl2Si2O8
9.EG.20KampfiteBa12(Si11Al5)O31(CO3)8Cl5
9.EG.25SträtlingiteCa2Al2SiO7 · 8H2O
9.EG.25VertumniteCa4Al4Si4O6(OH)24 · 3H2O
9.EG.30Eggletonite(Na,K,Ca)2(Mn,Fe)8(Si,Al)12O29(OH)7 · 11H2O
9.EG.30Ganophyllite(K,Na,Ca)2Mn8(Si,Al)12(O,OH)32 · 8H2O
9.EG.30Tamaite(Ca,K,Ba,Na)3-4Mn24(Si,Al)40(O,OH)112 · 21H2O
9.EG.35CoombsiteK(Mn,Fe,Mg)13(Si,Al)18O42(OH)14
9.EG.35ZussmaniteK(Fe,Mg,Mn)13(Si,Al)18O42(OH)14
9.EG.40Franklinphilite(K,Na)4(Mn,Zn,Mg,Fe)48(Si,Al)72(O,OH)216 · 6H2O
9.EG.40LennilenapeiteK6-7(Mg,Mn,Fe,Zn)48(Si,Al)72(O,OH)216 · 16H2O
9.EG.40Parsettensite(K,Na,Ca)7.5(Mn,Mg)49Si72O168(OH)50 · nH2O
9.EG.45Latiumite(Ca,K)4(Si,Al)5O11(SO4,CO3)
9.EG.45Tuscanite(K(Ca,Na)6(Si,Al)10O22[SO4,CO3,(OH)2] · H2O
9.EG.50JagoitePb18Fe43+[Si4(Si,Fe3+)6][Pb4Si16(Si,Fe)4]O82Cl6
9.EG.55WickenburgiteCaPb3Al2Si10O24(OH)6
9.EG.60HyttsjöitePb18Ba2Ca5Mn22+Fe23+Si30O90Cl · 6H2O
9.EG.65ArmbrusteriteK5Na7Mn15[(Si9O22)4](OH)10 · 4H2O
9.EG.70Britvinite[Pb7(OH)3F(BO3)2(CO3)][Mg4.5(OH)3(Si5O14)]
9.EG.75BannisteriteCa0.5(K,Na)0.5(Mn,Fe,Zn)10(Si,Al)16O38(OH)8 · 5.5H2O
16.20.1Glaucophane◻[Na2][Mg3Al2]Si8O22(OH)2
16.20.2Sodium-anthophyllite
16.20.3Sodium Gedrite
16.20.4Crossite
16.20.5Ferro-eckermanniteNaNa2(Fe2+,4Al)Si8O22(OH)2
16.20.6Wonesite(Na,K)(Mg,Fe,Al)6((Al,Si)4O10)2(OH,F)4
16.20.8LennilenapeiteK6-7(Mg,Mn,Fe,Zn)48(Si,Al)72(O,OH)216 · 16H2O
16.20.10Glauconite(K,Na)(Fe3+,Al,Mg)2(Si,Al,Fe3+)4O10)(OH)2

Other Names for Stilpnomelane

Name in Other Languages:
Simplified Chinese:黑硬绿泥石
Spanish:Minguétita
Traditional Chinese:黑硬綠泥石

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.

References for Stilpnomelane

Reference List:
Beitr. mineral. Kenntnis Sudetenländer (1827): pt. 1, p. 68.

Hutton, Colin Osborne (1956): Further data on the stilpnomelane mineral group: American Mineralogist: 41: 608-615.

Smith, M.L. and Frondel, C. (1968): The related layered minerals ganophyllite, bannisterite and stilpnomelane. Mineralogical Magazine: 36: 893-913.

Mineralogical Magazine (1978): 42: 361-368.

Internet Links for Stilpnomelane

Localities for Stilpnomelane

map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the symbol to view information about a locality. The symbol next to localities in the list can be used to jump to that position on the map.
Mineral and/or Locality  
Mindat.org is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization.
Copyright © mindat.org and the Hudson Institute of Mineralogy 1993-2015, except where stated. Mindat.org relies on the contributions of thousands of members and supporters.
Privacy Policy - Terms & Conditions - Contact Us Current server date and time: July 1, 2015 13:10:12 Page generated: June 19, 2015 11:13:19