Rilandite
A valid IMA mineral species - grandfathered - questionable
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About Rilandite
Formula:
Cr6SiO11 · 5H2O (?)
Also given as Cr4Al2SiO11 · 5H2O or near.
Colour:
dark brownish black
Lustre:
Dull
Hardness:
2 - 3
Name:
Named after James L. Riland (May 5, 1857 Pine Grove, Pennsylvania, USA - October 15, 1936 Meeker Colorado, USA) newspaper publisher and miner of Meeker, Colorado, USA.
This page provides mineralogical data about Rilandite.
Unique Identifiers
Mindat ID:
3419
Long-form identifier:
mindat:1:1:3419:3
Similar Names
| Rollandite | A valid IMA mineral species | Cu3(AsO4)2 · 4H2O |
| Rowlandite-(Y) | A valid IMA mineral species - grandfathered | (Y,Ce)4Fe2+(Si2O7)2F2 (?) |
IMA Classification of Rilandite
Approved, 'Grandfathered' (first described prior to 1959), Questionable
IMA Formula:
Cr3+6SiO11·5H2O
Classification of Rilandite
9.HB.10
9 : SILICATES (Germanates)
H : Unclassified silicates
B : With Ti, V, Cr
9 : SILICATES (Germanates)
H : Unclassified silicates
B : With Ti, V, Cr
7.11.14.1
7 : MULTIPLE OXIDES
11 : Miscellaneous
7 : MULTIPLE OXIDES
11 : Miscellaneous
16.15.4
16 : Silicates Containing Aluminum and other Metals
15 : Aluminosilicates of V and Cr
16 : Silicates Containing Aluminum and other Metals
15 : Aluminosilicates of V and Cr
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 |
|---|---|---|
| Ril | 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 Rilandite
Dull
Transparency:
Translucent
Comment:
Brilliant on fresh surface, otherwise dull, pitchy
Colour:
Dark brownish black
Streak:
Grayish brown
Hardness:
2 - 3 on Mohs scale
Tenacity:
Brittle
Fracture:
Conchoidal
Chemistry of Rilandite
Mindat Formula:
Cr6SiO11 · 5H2O (?)
Also given as Cr4Al2SiO11 · 5H2O or near.
Also given as Cr4Al2SiO11 · 5H2O or near.
Elements listed:
Common Impurities:
Fe,Mg,Ca
Crystallography of Rilandite
Morphology:
Subhedral, angular and platy; compact, massive.
Comment:
Crystal Data: n.d. Point Group: n.d.; Space Group: n.d. Z = n.d.
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 7: Great Oxidation Event | <2.4 |
| 47a : [Near-surface hydration of prior minerals] | |
| 47e : [Vanadates, chromates, manganates] | |
| Stage 10a: Neoproterozoic oxygenation/terrestrial biosphere | <0.6 |
| 53 : Other minerals with taphonomic origins | <0.4 |
Type Occurrence of Rilandite
Place of Conservation of Type Material:
National Museum of Natural History, Washington, D.C., USA, 96808.
Associated Minerals at Type Locality:
Other Language Names for Rilandite
Related Minerals - Strunz-mindat Grouping
| 9.HB. | Waipouaite | Ca3V4+5O9[Si2O5(OH)2][Si3O7(OH)2] · 11H2O |
| 9.HB.05 | Ilmajokite-(Ce) | Na11KBaCe2Ti12Si37.5O94(OH)31 · 29H2O |
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 Rilandite
mindat.org URL:
https://www.mindat.org/min-3419.html
Please feel free to link to this page.
Please feel free to link to this page.
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References for Rilandite
Localities for Rilandite
Showing 1 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.
USA (TL) | |
| Eckel et al. (1997) |
Riland uranium claim, Meeker, Rio Blanco County, Colorado, USA