Mindat Logo

Steacyite

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



Formula:
(◻,K)(Na,Ca)
 
2
(Th,U)[Si
 
8
O
 
20
]
System:TetragonalColour:Gray, dark brown, green, ...
Hardness:5
Member of:Steacyite Group
Name:Named in 1982 by Guy Perrault and Jan T. Szymaňski in honor of Harold Robert Steacy [June 7, 1923 Ottawa, Ontario, Canada - April 7, 2012 Ottawa, Ontario, Canada], mineralogist, former Curator of the National Mineral Collection, Geological Survey of Canada, for his contributions to Canadian mineralogy.
This page provides mineralogical data about Steacyite.

Classification of Steacyite

IMA status:Approved 1981
Strunz 8th edition ID:8/E.10-30
Nickel-Strunz 10th (pending) edition ID:9.CH.10

9 : SILICATES (Germanates)
C : Cyclosilicates
H : [Si4O12]8- 4-membered double rings
Dana 8th edition ID:63.1.1.1

63 : CYCLOSILICATES Condensed Rings
1 : Condensed Rings (Steacyite group)
Hey's CIM Ref.:14.16.15

14 : Silicates not Containing Aluminum
16 : Silicates of U
mindat.org URL:http://www.mindat.org/min-3754.html
Please feel free to link to this page.

Type Occurrence of Steacyite

Type Locality:Poudrette quarry (Demix quarry; Uni-Mix quarry; Desourdy quarry; Carrière Mont Saint-Hilaire), Mont Saint-Hilaire, La Vallée-du-Richelieu RCM, Montérégie, Québec, Canada
Year of Discovery:1981

Physical Properties of Steacyite

Lustre:Vitreous, Greasy, Dull
Diaphaneity (Transparency):Translucent, Opaque
Colour:Gray, dark brown, green, beige
Hardness (Mohs):5

Crystallography of Steacyite

Crystal System:Tetragonal
Cell Parameters:a = 7.58Å, c = 14.76Å
Ratio:a:c = 1 : 1.947
Unit Cell Volume:V 848.06 ų (Calculated from Unit Cell)

Optical Data of Steacyite

Type:Uniaxial (-)
RI values: nω = 1.573 nε = 1.572
Maximum Birefringence:δ = 0.001

Chart shows birefringence interference colour range (at 30µm thickness) and does not take into account mineral colouration.
Surface Relief:Low

Chemical Properties of Steacyite

Formula:
(◻,K)(Na,Ca)
 
2
(Th,U)[Si
 
8
O
 
20
]
Simplified for copy/paste:(◻,K)(Na,Ca)2(Th,U)[Si8O20]
Essential elements:Na, O, Si, Th
All elements listed in formula:Ca, K, Na, O, Si, Th, U
Common Impurities:As,Mn,Pb,F,P

Relationship of Steacyite to other Species

Member of:Steacyite Group
Other Members of Group:

- +
Arapovite
(K,◻)(Ca,Na)
 
2
(U,Th)[Si
 
8
O
 
20
] · H
 
2
O
Iraqite-(La)
K(Ca,Na)
 
2
(La,Ce,Th)[(Si,Al)
 
8
O
 
20
]
Turkestanite
(K,◻)(Ca,Na)
 
2
(Th,U)[Si
 
8
O
 
20
] · nH
 
2
O
Related Minerals - Nickel-Strunz Grouping):

- +
9.CH.05Hyalotekite
(Pb,Ba,K)
 
4
(Ca,Y)
 
2
(B,Be)
 
2
(Si,B)
 
2
Si
 
8
O
 
28
(F,Cl)
9.CH.05Kapitsaite-(Y)
(Ba,K,Pb)
 
4
(Y,Ca)
 
2
Si
 
8
(B,Si)
 
4
O
 
28
F
9.CH.10Iraqite-(La)
K(Ca,Na)
 
2
(La,Ce,Th)[(Si,Al)
 
8
O
 
20
]
9.CH.10Turkestanite
(K,◻)(Ca,Na)
 
2
(Th,U)[Si
 
8
O
 
20
] · nH
 
2
O
9.CH.10Arapovite
(K,◻)(Ca,Na)
 
2
(U,Th)[Si
 
8
O
 
20
] · H
 
2
O
Related Minerals - Hey's Index Grouping:

- +
14.16.1Uranosilite
UO
 
3
· 7SiO
 
2
14.16.2Coffinite
(U
4+
 
,Th)(SiO
 
4
)
 
1-x
(OH)
 
4x
14.16.3Soddyite
(UO
 
2
)
 
2
SiO
 
4
· 2H
 
2
O
14.16.4Swamboite
UH
 
6
(UO
 
2
)
 
6
(SiO
 
4
)
 
6
· 30H
 
2
O
14.16.5Weeksite
K
 
2
(UO
 
2
)
 
2
(Si
 
5
O
 
13
) · 4H
 
2
O
14.16.6Boltwoodite
(K,Na)(UO
 
2
)[HSiO
 
4
] · 0.5H
 
2
O
14.16.7Natroboltwoodite
(H
 
3
O)(Na,K)UO
 
2
SiO
 
4
· H
 
2
O
14.16.8Cuprosklodowskite
Cu(UO
 
2
)
 
2
[HSiO
 
4
]
 
2
· 6H
 
2
O
14.16.9Sklodowskite
Mg(UO
 
2
)
 
2
[HSiO
 
4
]
 
2
· 5H
 
2
O
14.16.10Uranophane
Ca(UO
 
2
)
 
2
[HSiO
 
4
]
 
2
· 5H
 
2
O
14.16.11β-Uranophane
Ca(UO
 
2
)
 
2
(HSiO
 
4
)
 
2
· 5H
 
2
O
14.16.12Haiweeite
Ca(UO
 
2
)
 
2
[Si
 
5
O
 
12
(OH)
 
2
] · 6H
 
2
O
14.16.13Metahaiweeite
Ca(UO
 
2
)
 
2
Si
 
6
O
 
15
· nH
 
2
O
14.16.14Thorogummite
(Th,U)(SiO
 
4
)
 
1-x
(OH)
 
4x
14.16.16Ekanite
(Ca,Fe
2+
 
,Pb)
 
2
(Th,U)[Si
 
8
O
 
20
]
14.16.17Kasolite
Pb(UO
 
2
)[SiO
 
4
] · H
 
2
O
14.16.18Orlite
Pb
 
3
(UO
 
2
)
 
3
(Si
 
2
O
 
7
)
 
2
· 6H
 
2
O
14.16.19Oursinite
(Co,Mg)(UO
 
2
)
 
2
[HSiO
 
4
]
 
2
· 6H
 
2
O

Other Names for Steacyite

Synonyms:
IMA1981-EUnnamed (MSH UK-4)
Other Languages:
German:Steacyit
Russian:Стисиит
Simplified Chinese:斯硅钾钍钙石
Spanish:Steacyita
Traditional Chinese:斯矽鉀釷鈣石

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 Steacyite

Reference List:

- +
PERRAULT, G., and SZYMAŃSKI, J.T. (1982) Steacyite, a new name and a re- evaluation of the nomenclature of "ekanite" group minerals. Canadian Mineralogist, 20, 59-63.
SZYMAŃSKY, J.T., OWENS, D.R., ROBERTS, A.C., ANSELL, H.G., and CHAO, G.Y. (1982) A mineralogical study and crystal structure determination of nonmetamict ekanite ThCa2Si8O20. Canadian Mineralogist, 20, 65-75.

Internet Links for Steacyite

Search Engines:
  • Look for Steacyite on Google
  • Look for Steacyite images on Google
  • External Links:
  • Look for Steacyite on Webmineral
  • Look for Steacyite on Athena Mineralogy
  • Look for Steacyite on Wikipedia
  • Look for Steacyite on Mineralien Atlas
  • Raman and XRD data at RRUFF project
  • American Mineralogist Crystal Structure Database
  • Steacyite details from Handbook of Mineralogy (PDF)
  • Mineral Dealers:
  • rare and unusual minerals mainly crystallized
  • Rare and Unusual minerals at Mineralogical Research Company
  • Mineral Classics - Worldwide Collector Quality Minerals and Gems
  • DAKOTA MATRIX offers Cabinet and Rare Species from Worldwide Localities.
  • Top quality minerals from Kristalle of California
  • Wilensky Fine Minerals
  • Find Steacyite on www.crystalclassics.co.uk
  • Buy RARE Minerals from Rocks of Africa
  • Search for Steacyite on Well-Arranged Molecules
  • Fine and rare minerals from mintreasure.com
  • High-end worldwide specimens & outstanding customer service
  • The Arkenstone - Fine Minerals
  • Specimens:The following Steacyite specimens are currently listed for sale on minfind.com.

    Localities for Steacyite

    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.
    (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.
    Canada
     
    • Québec
      • Montérégie
        • La Vallée-du-Richelieu RCM
          • Mont Saint-Hilaire
    PERRAULT, G., and SZYMAŃSKI, J.T. (1982)Steacyite, a new name and a re- evaluation of the nomenclature of "ekanite" group minerals. Canadian Mineralogist, 20, 59-63. Horváth, L and Gault, R.A. (1990), The mineralogy of Mont Saint-Hilaire Quebec. Mineralogical Record: 21: 284-359.
    Germany
     
    • Rhineland-Palatinate
      • Eifel
        • Laach lake volcanic complex
          • Kruft
    Blass, G.; Graf, H.W., Neufunde von bekannten Fundorten (IX), Mineralien-Welt 5/1,18, 1994
          • Mendig
            • Niedermendig
    Blass, G.; Graf, H.W., Neufunde von bekannten Fundorten (IX), Mineralien-Welt 5/1,18, 1994
    Blass, G.; Graf, H.W., Neufunde von bekannten Fundorten (IX), Mineralien-Welt 5/1,18, 1994
              • Wingertsberg
    Blass, G.; Graf, H.W., Neufunde von bekannten Fundorten (IX), Mineralien-Welt 5/1,18, 1994
    Greenland
     
    • Kujalleq
      • Narsaq
        • Igaliku (Igaliko)
          • Narsaarsuk Plateau
    Knut Eldjarn ( XRD Geological museum, Oslo)+ chemical (ICP)
    Guinea
     
    Parodi, G. C., & Della Ventura, G. (1987). Steacyite from the Rouma Isle (Los Islands, Republic of Guinea). Neues Jarbuch fur Mineralogie, Mh., Jg. 1987, H. 5, 233-239
    Parodi, G. C., & Della Ventura, G. (1987). Steacyite from the Rouma Isle (Los Islands, Republic of Guinea). Neues Jarbuch fur Mineralogie, Mh., Jg. 1987, H. 5, 233-239. ; Moreau, C., Ohnenstetter, D., Demaiffe, D., & Robineau, B. (1996). The Los Archipelago nepheline syenite ring-structure; a magmatic marker of the evolution of the Central and Equatorial Atlantic. The Canadian Mineralogist, 34(2), 281-299.; Biagioni, C., Bonaccorsi, E., Merlino, S., Parodi, G. C., Perchiazzi, N., Chevrier, V., & Bersani, D. (2010). Roumaite,(Ca, Na,□) 3 (Ca, REE, Na) 4 (Nb, Ti)[Si2O7] 2 (OH) F3, from Rouma Island, Los Archipelago, Guinea: a new mineral species related to dovyrenite. The Canadian Mineralogist, 48(1), 17-28.
    Namibia
     
    • Khomas Region
      • Windhoek District
        • Aris
    Joachim Esche collection (SEM-EDS-analysed) Horváth collection XRD & EDS analyzed
    Russia
     
    • Eastern-Siberian Region
      • Sakha Republic (Saha Republic; Yakutia)
        • Aldan Shield
          • Chara and Tokko Rivers Confluence
    Konev, A.A., Vorob'yev, E.I., and Lazebnik, K.A. (1996) The Mineralogy of the Murun Massif. Russian Academy of Science Press, Siberian Branch, Novosbirsk, Russia (in Rus.)
    Pavel M. Kartashov data
    • Northern Region
      • Murmanskaja Oblast'
        • Kola Peninsula
          • Khibiny Massif
    Pekov, I.V. & Podlesnyi, A.S. (2004): Kukisvumchorr Deposit: Mineralogy of Alkaline Pegmatites and Hydrotermalites. Mineralogical Almanac, vol. 7, 140 pages + xxiv photo's pages
    USA
     
    Minerological Record 18: 361n
    Mineral and/or Locality  
    Search Google  
    Copyright © Jolyon Ralph and Ida Chau 1993-2014. Site Map. Locality, mineral & photograph data are the copyright of the individuals who submitted them. 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 thousands 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: July 19, 2014 17:12:14
    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