Mindat Logo
Home Page Log In Messageboard The Mindat Directory
Register Search Pages Mineral Chatroom The Mindat Store

Olmsteadite

This page is currently not sponsored. Click here to sponsor this page.
Big Photo

White Cap Mine (King Mica Mine; Primer), Keystone, Keystone District, Pennington Co., South Dakota, USA

Show Olmsteadite Photos (3)



Formula:
KFe
2+
2
(Nb
5+
 
,Ta
5+
 
)(PO
 
4
)
 
2
O
 
2
 · 2H
 
2
O
System:OrthorhombicHardness:4
Name:Honoring Milo Olmstead, Rapid City, South Dakota, USA, amateur collector of microscopic minerals, who called attention to the mineral.


The Fe analogue of johnwalkite.

Classification of Olmsteadite

IMA status:Approved 1974
Strunz 8th edition ID:7/D.39-10
Nickel-Strunz 10th (pending) edition ID:8.DJ.05

8 : PHOSPHATES, ARSENATES, VANADATES
D : Phosphates, etc. with additional anions, with H2O
J : With large and medium-sized cations, (OH, etc.):RO4 = 1:1
Dana 8th edition ID:42.7.11.1

42 : HYDRATED PHOSPHATES, ETC.CONTAINING HYDROXYL OR HALOGEN
7 : (AB)2(XO4)Zq·xH2O
Hey's CIM Ref.:22.5.13

22 : Phosphates, Arsenates or Vanadates with other Anions
5 : Phosphates, arsenates or vanadates with chromate, molybdate, niobate or tantalate
mindat.org URL:http://www.mindat.org/min-2986.html
Please feel free to link to this page.

Type Occurrence of Olmsteadite

Type Locality:Big Chief Mine (Johnson pegmatite), Glendale, Keystone District, Pennington Co., South Dakota, USA
Place of Conservation of Type Material:National Museum of Natural History, Washington, D.C., USA, 135924.
Year of Discovery:1976

Physical Properties of Olmsteadite

Hardness (Mohs):4

Crystallography of Olmsteadite

Crystal System:Orthorhombic
Cell Parameters:a = 7.47Å, b = 10.03Å, c = 6.53Å
Ratio:a:b:c = 0.745 : 1 : 0.651
Unit Cell Volume:V 489.25 ų (Calculated from Unit Cell)
Crystal Atlas:
Image Loading
Click on an icon to view
Olmsteadite - Tabular {001}
Olmsteadite - Tabular {100}

About Crystal Atlas

You may need to scroll this box using your mouse to view the full instructions.

The mindat.org Crystal Atlas allows you to view a selection of crystal drawings of real and idealised crystal forms for this mineral and, in certain cases, 3d rotating crystal objects. You need Java to see these. You can download Java for free - click here to download Java

The 3d models and java code are kindly provided by www.smorf.nl. You can control the movement of the models by holding down the left mouse-button over the 3d model and moving your mouse. Keyboard controls are:

: default positions
t/T: decrease/increase transparency x/X: next/previous texture
b/B: next/previous background w: toggle wireframe
s: toggle sticks m: toggle miller indices
k: toggle crystallographic axes =/-: zoom in/out
r: stop/start rotation 1/2/3

Optical Data of Olmsteadite

Type:Biaxial (+)
RI values: nα = 1.725 - 1.765 nβ = 1.755 - 1.775 nγ = 1.815 - 1.835
2V:Measured: 60° , Calculated: 46° to 74°
Maximum Birefringence:δ = 0.090

Chart shows birefringence interference colour range (at 30µm thickness) and does not take into account mineral colouration.
Surface Relief:High
Dispersion:r > v moderate

Chemical Properties of Olmsteadite

Formula:
KFe
2+
2
(Nb
5+
 
,Ta
5+
 
)(PO
 
4
)
 
2
O
 
2
 · 2H
 
2
O
Essential elements:Fe, H, K, Nb, O, P
All elements listed in formula:Fe, H, K, Nb, O, P, Ta

Relationship of Olmsteadite to other Species

Related Minerals - Nickel-Strunz Grouping):

- +
8.DJ.05Johnwalkite
K(Mn
2+
 
,Fe
2+
 
,Fe
3+
 
)
 
2
(Nb
5+
 
,Ta
5+
 
)(PO
 
4
)
 
2
O
 
2
 · 2(H
 
2
O,OH)
8.DJ.10Gatumbaite
CaAl
 
2
(PO
 
4
)
 
2
(OH)
 
2
 · H
 
2
O
8.DJ.15Camgasite
CaMg(AsO
 
4
)(OH) · 5H
 
2
O
8.DJ.20Phosphofibrite
K
 
<0.5
(Fe
3+
 
,Cu)
 
8
(PO
 
4
)
 
6
(OH)
 
7
 · 7H
 
2
O
8.DJ.20Meurigite-K
KFe
3+
8
(PO
 
4
)
 
6
(OH)
 
7
 · 6.5H
 
2
O
8.DJ.20Meurigite-Na
NaFe
3+
8
(PO
 
4
)
 
6
(OH)
 
7
 · 6.5H
 
2
O
8.DJ.25Jungite
Ca
 
2
Zn
 
4
Fe
3+
8
(PO
 
4
)
 
9
(OH)
 
9
 · 16H
 
2
O
8.DJ.30Wycheproofite
NaAlZr(PO
 
4
)
 
2
(OH) · H
 
2
O
8.DJ.35Ercitite
Na
 
2
Mn
3+
2
(PO
 
4
)
 
2
(OH)
 
2
 · 4H
 
2
O
8.DJ.40Mrázekite
Bi
 
2
Cu
 
3
(PO
 
4
)
 
2
O
 
2
(OH)
 
2
 · H
 
2
O
8.DJ.45Attikaite
Ca
 
3
Cu
 
2
Al
 
2
(AsO
 
4
)
 
4
(OH)
 
4
 · 2H
 
2
O
Related Minerals - Hey's Index Grouping:

- +
22.5.1Vauquelinite
Pb
 
2
Cu(CrO
 
4
)(PO
 
4
)(OH)
22.5.2Embreyite
Pb
 
5
(CrO
 
4
)
 
2
(PO
 
4
)
 
2
 · H
 
2
O
22.5.3Cassedanneite
Pb
 
5
(CrO
 
4
)
 
2
(VO
 
4
)
 
2
 · H
 
2
O
22.5.4Fornacite
Pb
 
2
Cu(CrO
 
4
)(AsO
 
4
)(OH)
22.5.5Molybdofornacite
Pb
 
2
Cu(MoO
 
4
,CrO
 
4
)(AsO
 
4
,PO
 
4
)(OH)
22.5.6Mendozavilite-NaFe
Na(Ca,Mg)
 
2
Fe
3+
6
(PMo
 
11
O
 
39
)(PO
 
4
)
 
2
(OH,Cl)
 
10
 · 33H
 
2
O
22.5.7Paramendozavilite
NaAl
 
4
Fe
3+
7
(PMo
 
12
O
 
40
)(PO
 
4
)
 
5
(OH)
 
16
 · 56H
 
2
O
22.5.8Betpakdalite-CaCa
{Mg(H
 
2
O)
 
6
}Ca
 
2
(H
 
2
O)
 
13
[Mo
6+
8
As
5+
2
Fe
3+
3
O
 
36
(OH)](H
 
2
O)
 
4
22.5.9Betpakdalite-NaCa
(Na
 
2
,Ca)Fe
 
2
(As
 
2
Mo
 
6
O
 
28
) · 15H
 
2
O
22.5.10Obradovicite-KCu
H
 
4
(K,Na)CuFe
 
2
(MoO
 
4
)
 
5
(AsO
 
4
) · 12H
 
2
O
22.5.11Melkovite
CaFe
3+
2
Mo
 
5
(PO
 
4
)
 
2
O
 
10
(OH)
 
12
 · 8H
 
2
O
22.5.12Rankachite
Ca
 
0.5
(V
4+
 
,V
5+
 
)(W
6+
 
,Fe
3+
 
)
 
2
O
 
8
(OH) · 2H
 
2
O
22.5.14Johnwalkite
K(Mn
2+
 
,Fe
2+
 
,Fe
3+
 
)
 
2
(Nb
5+
 
,Ta
5+
 
)(PO
 
4
)
 
2
O
 
2
 · 2(H
 
2
O,OH)

Other Names for Olmsteadite

Synonyms:
IMA1974-034
Other Languages:
German:Olmsteadit
Russian:Олмстедит
Spanish:Olmsteadita

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 Olmsteadite

Reference List:

- +
Moore, P. B., Araki, T., Kampf, A. R. & Steele, I. M. (1976) Olmsteadite, K2Fe2+2[Fe2+2(Nb,Ta)5+2O4(H2O)4(PO4)4], a new species, its crystal structure and relation to vauxite and montgomeryite. American Mineralogist, 61, 5-11.

Internet Links for Olmsteadite

Search Engines:
  • Look for Olmsteadite on Google
  • Look for Olmsteadite images on Google
    • External Links:
  • Look for Olmsteadite on Webmineral
  • Look for Olmsteadite on Mineralien Atlas
  • Raman and XRD data at RRUFF project
  • American Mineralogist Crystal Structure Database
  • Olmsteadite details from Handbook of Mineralogy (PDF)
    • Mineral Dealers:
  • Find Olmsteadite on www.crystalclassics.co.uk
  • DAKOTA MATRIX offers Cabinet and Rare Species from Worldwide Localities.
  • Minerals from Darwin Natural History
  • Search for minerals at Heliodor
  • Search for Olmsteadite on Well-Arranged Molecules
  • Fabre Minerals - search for Olmsteadite specimens
  • The Arkenstone - Fine Minerals
  • High-end worldwide specimens & outstanding customer service
  • Olmsteadite specimens for sale - minfind.com
  • Buy fine minerals and gemstones from Pala International
  • Top quality minerals from Kristalle of California
  • Fine Minerals from Weinrich Minerals, Inc.
    • Jobs:
  • Mining & Geology Jobs

    • Localities for Olmsteadite

    The 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.
    Hide Locality List
    (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.
    USA
     
    • South Dakota
      • Pennington Co.
        • Keystone District
          • Glendale
    		American Mineralogist, Volume 61, pages 5-ll, 1976
    American Mineralogist, Volume 61, pages 5-ll, 1976
          • Keystone
    		Handbook of Mineralogy - Anthony, Bideaux, Bladh, Nichols
    Mineral and/or Locality
    Search Google
     
    Copyright © Jolyon Ralph and Ida Chau 1993-2012. 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. Mindat does not offer minerals for sale. If you would like to add information to improve the quality of our database, then click here to register.
    Current server date and time: 9th Mar 2012 18:56:40
    Mineral and Locality Search
    Mineral:
    and/or Locality:
    Options
    Fade toolbar when not in focusFix toolbar to bottom of page
    Hide Social Media Links
    Slideshow frame delay seconds