Mindat Logo
Home Page Log In Message Board The Mindat Directory
Register Search Pages Chat Now! (2 online) Mindat Auctions

Koktaite

Big Photo

Žeravice, South Moravia Region, Moravia (Mähren; Maehren), Czech Republic
© Leon Hupperichs

Show Koktaite Photos (7)
Formula:
(NH
 
4
)
 
2
Ca(SO
 
4
)
 
2
·H
 
2
O
System:MonoclinicColour:Colourless, white.
Name:After Jaroslav Kokta (1904-1970), Czech chemist who analyzed the artificial compound.
This page provides mineralogical data about Koktaite.

Classification of Koktaite

IMA status:Valid - first described prior to 1959 (pre-IMA) - "Grandfathered"
Strunz 8th edition ID:6/C.21-70
Nickel-Strunz 10th (pending) edition ID:7.CD.35

7 : SULFATES (selenates, tellurates, chromates, molybdates, wolframates)
C : Sulfates (selenates, etc.) without additional anions, with H2O
D : With only large cations
Dana 8th edition ID:29.3.1.2

29 : HYDRATED ACID AND NORMAL SULFATES
3 : A2B(XO4)2·xH2O
Hey's CIM Ref.:25.4.11

25 : Sulphates
4 : Sulphates of Ca, Sr and Ba
mindat.org URL:http://www.mindat.org/min-2237.html
Please feel free to link to this page.

Type Occurrence of Koktaite

Type Locality:Žeravice, South Moravia Region, Moravia (Mähren; Maehren), Czech Republic
General Appearance of Type Material:Pseudomorphs after gypsum.
Year of Discovery:1948
Geological Setting of type material:Waste piles of a lignite mine.
Associated Minerals at type locality:
GypsumTschermigiteMascagnite

Physical Properties of Koktaite

Diaphaneity (Transparency):Transparent, Translucent
Colour:Colourless, white.
Cleavage:None Observed
Density (measured):2.09 g/cm3

Crystallography of Koktaite

Crystal System:Monoclinic
Cell Parameters:a = 10.17Å, b = 7.15Å, c = 6.34Å
β = 102.75°
Ratio:a:b:c = 1.422 : 1 : 0.887
Unit Cell Volume:V 449.65 ų (Calculated from Unit Cell)
Morphology:Crystals acicular or fibrous-lamellar.
Twinning:On {100}, common.

Optical Data of Koktaite

Type:Biaxial (-)
RI values: nα = 1.524 nβ = 1.532 nγ = 1.536
2V:Measured: 72° , Calculated: 70°
Maximum Birefringence:δ = 0.012

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

Chemical Properties of Koktaite

Formula:
(NH
 
4
)
 
2
Ca(SO
 
4
)
 
2
·H
 
2
O
Essential elements:Ca, H, N, O, S
All elements listed in formula:Ca, H, N, O, S

Relationship of Koktaite to other Species

Related Minerals - Nickel-Strunz Grouping):

- +
7.CD.05Matteuccite
NaHSO
 
4
·H
 
2
O
7.CD.10Mirabilite
Na
 
2
SO
 
4
·10H
 
2
O
7.CD.15Lecontite
(NH
 
4
,K)Na(SO
 
4
)·2H
 
2
O
7.CD.20Hydroglauberite
Na
 
10
Ca
 
3
(SO
 
4
)
 
8
·6H
 
2
O
7.CD.25Eugsterite
Na
 
4
Ca(SO
 
4
)
 
3
·2H
 
2
O
7.CD.30Görgeyite
K
 
2
Ca
 
5
(SO
 
4
)
 
6
·H
 
2
O
7.CD.35Syngenite
K
 
2
Ca(SO
 
4
)
 
2
·H
 
2
O
7.CD.40Gypsum
Ca[SO
 
4
] · 2H
 
2
O
7.CD.45Bassanite
Ca[SO
 
4
] · 0.5H
 
2
O
7.CD.50Zircosulfate
(Zr,Ti)(SO
 
4
)
 
2
·4H
 
2
O
7.CD.55Schieffelinite
Pb
 
8
(TeO
 
4
)
 
5
(SO
 
4
)
 
3
·8H
 
2
O
7.CD.60Montanite
Bi
 
2
[TeO
 
6
] · 2H
 
2
O
7.CD.65Omongwaite
Na
 
2
Ca
 
5
(SO
 
4
)
 
6
·3H
 
2
O
Related Minerals - Hey's Index Grouping:

- +
25.4.1Anhydrite
CaSO
 
4
25.4.2Bassanite
Ca[SO
 
4
] · 0.5H
 
2
O
25.4.3Gypsum
Ca[SO
 
4
] · 2H
 
2
O
25.4.4Glauberite
Na
 
2
Ca(SO
 
4
)
 
2
25.4.5Cesanite
Na
 
3
Ca
 
2
[OH|(SO
 
4
)
 
3
]
25.4.6Eugsterite
Na
 
4
Ca(SO
 
4
)
 
3
·2H
 
2
O
25.4.7Hydroglauberite
Na
 
10
Ca
 
3
(SO
 
4
)
 
8
·6H
 
2
O
25.4.8Syngenite
K
 
2
Ca(SO
 
4
)
 
2
·H
 
2
O
25.4.9Görgeyite
K
 
2
Ca
 
5
(SO
 
4
)
 
6
·H
 
2
O
25.4.10Polyhalite
K
 
2
Ca
 
2
Mg(SO
 
4
)
 
4
·2H
 
2
O
25.4.12Ye'elimite
Ca
 
4
Al
 
6
[O
 
12
|SO
 
4
]
25.4.13Ettringite
Ca
 
6
Al
 
2
[(OH)
 
4
|SO
 
4
]
 
3
 · 26H
 
2
O
25.4.14Bentorite
Ca
 
6
(Cr
3+
 
,Al)
 
2
[(OH)
 
4
|SO
 
4
]
 
3
 · 26H
 
2
O
25.4.15Celestine
SrSO
 
4
25.4.16Kalistrontite
K
 
2
Sr(SO
 
4
)
 
2
25.4.17Baryte
BaSO
 
4

Other Names for Koktaite

Synonyms:
Ammonium-Syngenite
Other Languages:
German:Koktait
Russian:Коктаит
Spanish:Koktaita

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 Koktaite

Reference List:Sekanina (1948) Acta Ac. Sc. Nat. Moravo-Silesiacae: 20: no. 1.

American Mineralogist (1949): 34: 618.

Palache, C., Berman, H., & Frondel, C. (1951), The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana, Yale University 1837-1892, Volume II. John Wiley and Sons, Inc., New York, 7th edition, revised and enlarged: 444.

Periodico di Mineralogia (1985): 54: 29.

Internet Links for Koktaite

Search Engines:
  • Look for Koktaite on Google
  • Look for Koktaite images on Google
    • External Links:
  • Look for Koktaite on Webmineral
  • Look for Koktaite on Athena Mineralogy
  • Look for Koktaite on Wikipedia
  • Look for Koktaite on Mineralien Atlas
  • Raman and XRD data at RRUFF project
  • American Mineralogist Crystal Structure Database
  • Search for Koktaite in the Natural History Museum (London) online catalogue
  • Koktaite details from Handbook of Mineralogy (PDF)
    • Mineral Dealers:
  • rare and unusual minerals mainly crystallized
  • Buy from David K Joyce minerals
  • Edwards Minerals - Fine Specimens
  • Lapis Mineral Magazin
  • Wilensky Fine Minerals
  • Rare and Unusual minerals at Mineralogical Research Company
  • DAKOTA MATRIX offers Cabinet and Rare Species from Worldwide Localities.
  • Fine Minerals from Dan Weinrich Minerals
  • Buy Minerals and Crystals from Crystalarium.com
  • SpiriferMinerals.com - high quality specimens
  • The Arkenstone - Fine Minerals
  • Wendel Minerals - Auktion & Shop
    • Jobs:
  • Mining & Geology Jobs

    • Page Sponsor

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

    Localities for Koktaite

    Hide Locality List
    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.
    Czech Republic
     
    • Moravia (Mähren; Maehren)
      • South Moravia Region
    		Acta Acad.Sci.Nat. Moravo-Silesia (1948) 20, 1-26
    Germany
     
    • Thuringia
      • Gera
        • Ronneburg U deposit
    		T. Witzke & F. Rüger: Lapis 1998(7/8), 26-64
    Hungary
     
    • Baranya Co.
      • Mecsek Mts.
        • Pécs
    		Szakáll & Kovács,2007
    • Borsod-Abaúj-Zemplén Co.
      • Bükk Mts.
        • Miskolc
    		ACTA MIN. PETR. Suppl. Tomus XXXVIII., 1997
    Venezuela
     
    • Miranda
    		Urbani, 1997. Bol. Soc. Venezolana de Espeleología, no.30.
    Mineral and/or Locality
    Google
     
    www.mindat.org Web
    Copyright © Jolyon Ralph and Ida Chau 1993-2009. 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. If you would like to add information to improve the quality of our database, then click here to register. Current server date and time: 3rd Nov 2009 21:31:06