Okenite
A valid IMA mineral species - grandfathered
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About Okenite
Lorenz Oken
Formula:
Ca10Si18O46 · 18H2O
Colour:
White to slightly yellow, blue
Lustre:
Vitreous, Pearly
Hardness:
4½ - 5
Specific Gravity:
2.28 - 2.33
Crystal System:
Triclinic
Name:
Named in 1828 in honor of the German biologist Lorenz Oken (Lorenz Ocken) (August 1, 1779, Bohlsbach (now part of Offenburg), Ortenau, Baden, Germany - August 11, 1851, Zurich, Switzerland), professor at University of Munich, Germany and later professor at University of Zürich, Switzerland. The original name, ockenite, was later shortened to okenite. On September 11, 1802, "Lorenz Oken came up with a new system of animal classification that demonstrated the path of evolution." (From Cell Theory Timeline, http://www.timetoast.com/timelines/71438) In 1805, Oken was the first to recognize the significance of biological cell structure: "All living organisms originate from and consist of cells" (Lefalophodon: Welcome to NCEAS | NCEAS. Web. 04 Oct. 2011.) His full birth-name was Lorenz Okenfuss.
Type Locality:
WARNING: Many colourful specimens of Okenite, said to be from China or India, are currently available for sale. These are fake, the bright colours are artificial dyes added to the okenite.
Unique Identifiers
Mindat ID:
2967
Long-form identifier:
mindat:1:1:2967:0
Similar Names
| Ekanite | A valid IMA mineral species | Ca2ThSi8O20 |
| Odenite | A synonym of Biotite | |
| Oenite | A valid IMA mineral species | CoSbAs |
| Okenite (of Rink) | A synonym of Wollastonite | |
| Olenite | A valid IMA mineral species | NaAl3Al6(Si6O18)(BO3)3O3(OH) |
| Owenite | A synonym of 'Thuringite' |
IMA Classification of Okenite
Approved, 'Grandfathered' (first described prior to 1959)
IMA Formula:
Ca10Si18O46(H2O)18
First published:
1828
Classification of Okenite
9.EA.40
9 : SILICATES (Germanates)
E : Phyllosilicates
A : Single nets of tetrahedra with 4-, 5-, (6-), and 8-membered rings
9 : SILICATES (Germanates)
E : Phyllosilicates
A : Single nets of tetrahedra with 4-, 5-, (6-), and 8-membered rings
72.3.2.5
72 : PHYLLOSILICATES Two-Dimensional Infinite Sheets with Other Than Six-Membered Rings
3 : Two-Dimensional Infinite Sheets with Other Than Six-Membered Rings with 3-, 4-, or 5-membered rings and 8-membered rings
72 : PHYLLOSILICATES Two-Dimensional Infinite Sheets with Other Than Six-Membered Rings
3 : Two-Dimensional Infinite Sheets with Other Than Six-Membered Rings with 3-, 4-, or 5-membered rings and 8-membered rings
14.5.18
14 : Silicates not Containing Aluminum
5 : Silicates of Ca
14 : Silicates not Containing Aluminum
5 : Silicates of Ca
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 |
|---|---|---|
| Oke | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Pronunciation of Okenite
Pronunciation:
| Play | Recorded by | Country |
|---|---|---|
| Jolyon Ralph | United Kingdom |
Physical Properties of Okenite
Vitreous, Pearly
Transparency:
Transparent, Translucent
Colour:
White to slightly yellow, blue
Streak:
White
Hardness:
4½ - 5 on Mohs scale
Tenacity:
Elastic
Cleavage:
Perfect
on {001}
on {001}
Density:
2.28 - 2.33 g/cm3 (Measured) 2.33 g/cm3 (Calculated)
Optical Data of Okenite
Type:
Biaxial (-)
RI values:
nα = 1.512 - 1.532 nβ = 1.514 - 1.535 nγ = 1.515 - 1.542
2V:
Measured: 60° , Calculated: 68° to 70°
Max. Birefringence:
δ = 0.003 - 0.010
Based on recorded range of RI values above.
Based on recorded range of RI values above.
Interference Colours:
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
Surface Relief:
Low (negative)
Relative to Canada balsam mounting medium (n ≈ 1.537).
Relative to Canada balsam mounting medium (n ≈ 1.537).
This shows the grain boundary and Becke line effect under plane-polarised
light, based on the contrast between this mineral's average refractive
index and the mounting medium. It does not take into account mineral
colouration.
In focus
Interference Figure:
This shows the idealized biaxial acute bisectrix (Bxa) interference figure
- the conoscopic view for a grain cut perpendicular to the acute bisectrix, using
this mineral's 2V. The two small white dots mark the melatopes - the points
where the two optic axes emerge - and are shown only when they fall within the
field of view. The coloured bands are isochromatics, and the dark bands are
isogyres.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
Dispersion:
none
Chemistry of Okenite
Mindat Formula:
Ca10Si18O46 · 18H2O
Element Weights:
Elements listed:
Common Impurities:
Al,Fe,Sr,Na,K
Chemical Analysis
Oxide wt%:
| 1 | |
|---|---|
| SiO2 | 55.08 % |
| Al2O3 | 0.26 % |
| Fe2O3 | 0.20 % |
| CaO | 26.57 % |
| MgO | 0.12 % |
| Na2O | 0.76 % |
| K2O | 0.60 % |
| H2O | 16.13 % |
| CO2 | 0.32 % |
| Total: | 100.04 % |
Crystallography of Okenite
Crystal System:
Triclinic
Class (H-M):
1 - Pinacoidal
Space Group:
P1
Cell Parameters:
a = 9.69(1) Å, b = 7.28(1) Å, c = 22.02(4) Å
α = 92.7°, β = 100.1°, γ = 110.9°
α = 92.7°, β = 100.1°, γ = 110.9°
Ratio:
a:b:c = 1.331 : 1 : 3.025
Unit Cell V:
1,418.48 ų (Calculated from Unit Cell)
Z:
2
Morphology:
Bladed crystals to laths. Commonly as fibers.
Twinning:
About [010], composition plane {102}, lamellar
Crystal Structure
Load
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
Show
Big Balls | Small Balls | Just Balls | Spacefill
Polyhedra Off | Si Polyhedra | All Polyhedra
Remove metal-metal sticks
Big Balls | Small Balls | Just Balls | Spacefill
Polyhedra Off | Si Polyhedra | All Polyhedra
Remove metal-metal sticks
Display Options
Black Background | White Background
Perspective On | Perspective Off
2D | Stereo | Red-Blue | Red-Cyan
Black Background | White Background
Perspective On | Perspective Off
2D | Stereo | Red-Blue | Red-Cyan
View
CIF File Best | x | y | z | a | b | c
CIF File Best | x | y | z | a | b | c
Rotation
Stop | Start
Stop | Start
Labels
Console Off | On | Grey | Yellow
Console Off | On | Grey | Yellow
Data courtesy of the American Mineralogist Crystal Structure Database. Click on an AMCSD ID to view structure
| ID | Species | Reference | Link | Year | Locality | Pressure (GPa) | Temp (K) |
|---|---|---|---|---|---|---|---|
| 0000902 | Okenite | Merlino S (1983) Okenite, Ca10Si18O46*18H2O: the first example of a chain and sheet silicate American Mineralogist 68 614-622 |  | 1983 | Kolhapur District, Maharastra State, India | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 21 Å | (very very strong) |
| 8.8 Å | (very strong) |
| 3.56 Å | (very strong) |
| 2.93 Å | (very strong) |
| 3.07 Å | (strong) |
| 3.05 Å | (strong) |
| 2.98 Å | (moderately strong) |
| 2.77 Å | (moderately strong) |
Comments:
Mumbai, India. Data from Gard and Taylor (1956).
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 7: Great Oxidation Event | <2.4 |
| 47a : [Near-surface hydration of prior minerals] | |
| Stage 10a: Neoproterozoic oxygenation/terrestrial biosphere | <0.6 |
| 51 : Pyrometamorphic minerals (see also #54 and #56) | <0.36 |
Geological Setting:
Amygdules in basalts
Type Occurrence of Okenite
Synonyms of Okenite
Other Language Names for Okenite
Common Associates
Associations Based on Photo Data:
| 280 photos of Okenite associated with Gyrolite | NaCa16Si23AlO60(OH)8 · 14H2O |
| 102 photos of Okenite associated with Prehnite | Ca2Al2Si3O10(OH)2 |
| 90 photos of Okenite associated with Calcite | CaCO3 |
| 72 photos of Okenite associated with Quartz | SiO2 |
| 68 photos of Okenite associated with Apophyllite Group | AB4[Si8O20]X · 8H2O |
| 52 photos of Okenite associated with Hydroxyapophyllite-(K) | KCa4(Si8O20)(OH,F) · 8H2O |
| 50 photos of Okenite associated with Laumontite | CaAl2Si4O12 · 4H2O |
| 45 photos of Okenite associated with Chabazite-Ca | (Ca,K2,Na2)2[Al2Si4O12]2 · 12H2O |
| 40 photos of Okenite associated with Stilbite Subgroup | M6-7[Al8-9Si27-28O72] · nH2O |
| 24 photos of Okenite associated with Fluorapophyllite-(K) | KCa4(Si8O20)(F,OH) · 8H2O |
Related Minerals - Strunz-mindat Grouping
| 9.EA. | Hydroxymcglassonite-(K) | KSr4Si8O20(OH) · 8H2O |
| 9.EA. | Miyawakiite-(Y) | ◻Y4Fe2(Si8O20)(CO3)4(H2O)3 |
| 9.EA. | Bussyite-(Y) | (Y,REE,Ca)3(Na,Ca)6MnSi9Be5(O,OH,F)34 |
| 9.EA. | Hydroxyapophyllite-(NH4) | (NH4)Ca4(Si8O20)(OH)(H2O)8 |
| 9.EA. | Fluorapophyllite-(NH4) | NH4Ca4(Si8O20)F · 8H2O |
| 9.EA.05 | Gillespite | BaFe2+Si4O10 |
| 9.EA.05 | Cuprorivaite | CaCuSi4O10 |
| 9.EA.05 | Wesselsite | SrCuSi4O10 |
| 9.EA.05 | Effenbergerite | BaCuSi4O10 |
| 9.EA.07 | Fluorapophyllite-(Cs) | CsCa4(Si8O20)F · 8H2O |
| 9.EA.10 | Ekanite | Ca2ThSi8O20 |
| 9.EA.15 | Fluorapophyllite-(Na) | NaCa4(Si8O20)F · 8H2O |
| 9.EA.15 | Fluorapophyllite-(K) | KCa4(Si8O20)(F,OH) · 8H2O |
| 9.EA.15 | Hydroxyapophyllite-(K) | KCa4(Si8O20)(OH,F) · 8H2O |
| 9.EA.20 | Magadiite | Na2Si14O29 · 11H2O |
| 9.EA.25 | Dalyite | K2ZrSi6O15 |
| 9.EA.25 | Davanite | K2TiSi6O15 |
| 9.EA.30 | Sazhinite-(La) | Na3La[Si6O15] · 2H2O |
| 9.EA.30 | Sazhinite-(Ce) | Na3CeSi6O15 · 2H2O |
| 9.EA.35 | Armstrongite | CaZr[Si6O15] · 3H2O |
| 9.EA.45 | Perettiite-(Y) | Y2Mn4FeSi2B8O24 |
| 9.EA.45 | Nekoite | Ca3Si6O15 · 7H2O |
| 9.EA.45 | Badakhshanite-(Y) | Y2Mn4Al(Si2B7BeO24) |
| 9.EA.47 | Shlykovite | KCa[Si4O9(OH)] · 3H2O |
| 9.EA.50 | Diegogattaite | Na2CaCu2Si8O20 · H2O |
| 9.EA.50 | Cavansite | Ca(VO)Si4O10 · 4H2O |
| 9.EA.52 | Yangite | PbMnSi3O8 · H2O |
| 9.EA.55 | Pentagonite | Ca(VO)Si4O10 · 4H2O |
| 9.EA.60 | Penkvilksite | Na4Ti2Si8O22 · 4H2O |
| 9.EA.60 | Tumchaite | Na2Zr(Si4O11) · 2H2O |
| 9.EA.65 | Nabesite | Na2BeSi4O10 · 4H2O |
| 9.EA.70 | Ajoite | (K,Na)Cu7AlSi9O24(OH)6 · 3H2O |
| 9.EA.75 | Zeravshanite | Na2Cs4Zr3[Si18O45]*2H2O |
| 9.EA.80 | Bussyite-(Ce) | (Ce,REE)3(Na,H2O)6MnSi9Be5(O,OH)30F4 |
| 9.EA.85 | Plumbophyllite | Pb2Si4O10 · H2O |
Other Information
Thermal Behaviour:
Heated in a closed tube, yields water. Before the blowpipe, becomes opaque and white and fuses to a glass.
Notes:
Gelatinizes easily in HCl.
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 Okenite
mindat.org URL:
https://www.mindat.org/min-2967.html
Please feel free to link to this page.
Please feel free to link to this page.
Search Engines:
External Links:
Mineral Dealers:
References for Okenite
Reference List:
Tilley, C. E., Alderman, A. R. (1934) Progressive metasomatism in the flint nodules of the Scawt Hill contact-zone. Mineralogical Magazine and Journal of the Mineralogical Society, 23 (144) 513-518 doi:10.1180/minmag.1934.023.144.06
Gard, J. A., Taylor, H. F. W. (1956) Okenite and nekoite (a new mineral) Mineralogical Magazine and Journal of the Mineralogical Society, 31 (232) 5-20 doi:10.1180/minmag.1956.031.232.02
Phadke, Anant V., Kshirsagar, L. K. (1980) Thermal decomposition of okenite from India. Mineralogical Magazine, 43 (329) 677-679 doi:10.1180/minmag.1980.043.329.20
Localities for Okenite
Showing 95 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.
Antarctica | |
| Tschernich (1992) |
Australia | |
| R Bottrill coll. |
| Bottrill et al. (2008) |
| Bottrill et al. (2008) |
| Grguric et al. (2005) |
Austria | |
| Kolitsch (2008) +1 other reference |
| Postl et al. (1996) +1 other reference |
Azerbaijan | |
| Novgorodova M.I. (caspian Sea) |
Canada | |
| R Van Dommelen collection |
| R Van Dommelen collection | |
| Walker et al. (1922) | |
| Horváth Collection XRD ID |
| 179-181. +2 other references |
Chile | |
| Tschernich (1992) |
Costa Rica | |
| Micro Probe Volume VII Number 7 Spring ... +1 other reference |
Faroe Islands | |
| Merlino (1983) |
| Zeolite collection of Volker Betz +1 other reference |
| Schmitter (2008) | |
Germany | |
| Wittern (2001) |
| Weiß (1990) |
| Koritnig (1972) +1 other reference |
Greenland | |
| Clark (1993) |
| Bøggild (1953) | |
| Petersen et al. (2005) | |
| Bøggild (1953) | |
| Bøggild (1953) |
| von Kobell (1828) +1 other reference | |
| Bøggild (1953) | |
Hungary | |
| Szakáll et al. (1996) +1 other reference |
| KOVÁCS-PÁLFFY (2005) |
| KÓNYA (2015) |
| Kovács (2009) |
Iceland | |
| Betz (1981) |
| Selbekk et al. (2004) | |
India | |
| Ottens et al. (2022) |
| |
| Many specimens in many collections. ... +3 other references |
| Moore (2002) | |
| Clark (1993) | |
| www.johnbetts-fineminerals.com (2016) |
| |
| Lavinsky (n.d.) | |
| Arnav Khokarale Collection |
| Bayle (1998) |
| Haas (n.d.) | |
| Arnav Khokarale Collection |
| Mielke (n.d.) |
| Praszkier (2009) |
| Ottens et al. (2025) |
| Enrico Bonacina | |
Italy | |
| Stoppani et al. (1982) |
| Passaglia et al. (1995) +2 other references |
| Fabris et al. (2014) |
| Boscardin et al. (2000) +2 other references |
Japan | |
| Aoki (1984) |
| Momma et al. (2015) |
| Nishido et al. (1983) | |
Mexico | |
| Panczner (1987) |
Middle East | |
| Gross (1977) | |
New Zealand | |
| Museum Victoria Mineralogy Collection |
Norway | |
| Vogt (1935) +2 other references |
| Peter Andresen collection | |
| Nordrum (2004) | |
| Identified by XRD (pers. com to Knut Edvard Larsen 6.01.2023) |
Romania | |
| Marincea +4 other references |
| Szakáll |
| Szakáll et al. (2006) +1 other reference | |
| www.minerals-of-the carpathians.eu (2009) |
| Szakáll (2002) | |
Russia | |
| Levitsky (webmineral.ru) |
| Spiridonov et al. (2008) |
| Sergei F. Sluzhenikin data |
| ... |
Slovakia | |
| Martin Števko-unpublished |
UK | |
| Tilley et al. (1934) |
Ukraine | |
| Karpenko V. (New Data on Minerals) |
USA | |
| Shannon (1983) +1 other reference |
| Woodford et al. (1941) +1 other reference |
| Ream (2004) |
| Northrop et al. (1996) |
| Northrop et al. (1996) |
| Kenny Gay message 15.09.2005 +2 other references |
| The Adams Collection |
| Micro Probe Vol. 7 No. 2 Fall 1990 +1 other reference |
| Micro Probe Vol. 6 No. 5 Fall 1987 +1 other reference | |
| Bargar et al. (1986) +1 other reference |
| Colflesh (2010) |
| Bullock (1981) |
| Wilson (1995) +1 other reference |
| Bullock (1981) |
| U.S. GEOLOGICAL SURVEY PROFESSIONAL ... | |
| D. Allen Penick (1987) +1 other reference |
| - (n.d.) |
| Cannon (1975) +1 other reference |
| Bargar +1 other reference |
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Malad, Mumbai Suburban District, Salsette Island, Konkan Division, Maharashtra, India