Cebollite
A valid IMA mineral species - grandfathered - questionable
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About Cebollite
Cebolla Creek, Colorado, USA
Formula:
Ca5Al2(SiO4)3(OH)4
Colour:
Colorless, white, greenish gray, reddish brown
Lustre:
Dull
Hardness:
5
Specific Gravity:
2.96 (Calculated)
Crystal System:
Orthorhombic
Name:
Named for Cebolla Creek, "in whose drainage the mineral was collected." Pronounced cĕ-vŏi-'īte.
Low-temperature mineral formed by the deuteric alteration of melilite or plagioclase.
Often intergrown with natrolite.
Christie (1964) studied the type material by X-ray powder diffration. The obtained pattern was mainly that of a phase corresponding to synthetic "hydrovesuvianite" plus weak lines of melilite.
Compare also High-Hydrated Si-Deficient Vesuvianite.
Often intergrown with natrolite.
Christie (1964) studied the type material by X-ray powder diffration. The obtained pattern was mainly that of a phase corresponding to synthetic "hydrovesuvianite" plus weak lines of melilite.
Compare also High-Hydrated Si-Deficient Vesuvianite.
Unique Identifiers
Mindat ID:
924
Long-form identifier:
mindat:1:1:924:7
IMA Classification of Cebollite
Approved, 'Grandfathered' (first described prior to 1959), Questionable
First published:
1914
Classification of Cebollite
9.BB.10
9 : SILICATES (Germanates)
B : Sorosilicates
B : Si2O7 groups, without non-tetrahedral anions; cations in tetrahedral [4] and greater coordination
9 : SILICATES (Germanates)
B : Sorosilicates
B : Si2O7 groups, without non-tetrahedral anions; cations in tetrahedral [4] and greater coordination
78.1.1.1
78 : Unclassified Silicates
1 : Miscellaneous
78 : Unclassified Silicates
1 : Miscellaneous
16.9.15
16 : Silicates Containing Aluminum and other Metals
9 : Aluminosilicates of Ca
16 : Silicates Containing Aluminum and other Metals
9 : Aluminosilicates 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 |
|---|---|---|
| Cbl | 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 Cebollite
Dull
Transparency:
Translucent
Colour:
Colorless, white, greenish gray, reddish brown
Hardness:
5 on Mohs scale
Density:
2.96 g/cm3 (Calculated)
Optical Data of Cebollite
Type:
Biaxial (+)
RI values:
nα = 1.595 nβ = 1.60 nγ = 1.628
Max. Birefringence:
δ = 0.033
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:
High (positive)
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.
No measured or calculated 2V is on file for this mineral, so the value used here (46°) is estimated from its recorded refractive indices and optic sign, not from a direct 2V measurement.
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.
No measured or calculated 2V is on file for this mineral, so the value used here (46°) is estimated from its recorded refractive indices and optic sign, not from a direct 2V measurement.
Dispersion:
r > v strong
Chemistry of Cebollite
Mindat Formula:
Ca5Al2(SiO4)3(OH)4
Element Weights:
Common Impurities:
Na,K
Crystallography of Cebollite
Crystal System:
Orthorhombic
Morphology:
Fibrous aggregates.
Comment:
Orthorhombic (?). Point Group: n.d.; Space Group: n.d. Z = n.d.
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 3.49 Å | (30) |
| 3.29 Å | (80) |
| 3.08 Å | (90) |
| 2.90 Å | (100) |
| 2.73 Å | (50) |
| 2.58 Å | (50) |
| 2.47 Å | (30) |
| 2.33 Å | (50) |
| 2.28 Å | (60) |
| 2.14 Å | (40) |
| 1.753 Å | (70) |
| 1.712 Å | (50) |
| 1.548 Å | (30) |
| 1.485 Å | (50) |
| 1.464 Å | (60) |
Comments:
PXRD data from Kruger (1980).
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 3a: Earth’s earliest Hadean crust | >4.50 |
| 7 : Ultramafic igneous rocks | |
| 10 : Basalt-hosted zeolite minerals | |
| Stage 4b: Highly evolved igneous rocks | >3.0 |
| 36 : Carbonatites, kimberlites, and related igneous rocks | |
| Stage 7: Great Oxidation Event | <2.4 |
| 47a : [Near-surface hydration of prior minerals] |
Type Occurrence of Cebollite
General Appearance of Type Material:
compact masses of minute radiating fibers.
Place of Conservation of Type Material:
The Natural History Museum, London, England, 1923, 1022.
Harvard University, Cambridge, Massachusetts, 85726.
National Museum of Natural History (Smithsonian), Washington, D.C., USA, 87530, C3217, R6451.
Harvard University, Cambridge, Massachusetts, 85726.
National Museum of Natural History (Smithsonian), Washington, D.C., USA, 87530, C3217, R6451.
Geological Setting of Type Material:
alteration product of melilite in a carbonatite
Associated Minerals at Type Locality:
Other Language Names for Cebollite
Common Associates
Associations Based on Photo Data:
Related Minerals - Strunz-mindat Grouping
| 9.BB.10 | Hardystonite | Ca2Zn[Si2O7] |
| 9.BB.10 | Okayamalite | Ca2B[BSiO7] |
| 9.BB.10 | Jeffreyite | (Ca,Na)2(Be,Al)(Si2O7,HSi2O7) |
| 9.BB.10 | Alumoåkermanite | (CaNa)Al[Si2O7] |
| 9.BB.10 | Åkermanite | Ca2Mg[Si2O7] |
| 9.BB.10 | 'Ferri-gehlenite' | Ca2Fe3+[AlSiO7] |
| 9.BB.10 | Gehlenite | Ca2Al[AlSiO7] |
| 9.BB.10 | Ferroåkermanite | Ca2Fe[Si2O7] |
| 9.BB.10 | Hydroxylgugiaite | (Ca,◻)2(Si,Be)[(Be,Si)2O5.5(OH)1.5] |
| 9.BB.10 | Gugiaite | Ca2Be[Si2O7] |
| 9.BB.15 | Barylite | Be2Ba(Si2O7) |
| 9.BB.15 | 'Barylite-1O' | Be2Ba(Si2O7) |
| 9.BB.20 | Bennesherite | Ba2Fe2+[Si2O7] |
| 9.BB.20 | Andrémeyerite | BaFe2+2(Si2O7) |
Other Information
Notes:
Gelatinizes with acids and gives off water when heated in a closed tube.
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 Cebollite
mindat.org URL:
https://www.mindat.org/min-924.html
Please feel free to link to this page.
Please feel free to link to this page.
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External Links:
Mineral Dealers:
References for Cebollite
Reference List:
Kruger, F. J. (1980) The occurrence of cebollite in kimberlite and included zeolitized crustal xenoliths. Mineralogical Magazine, 43 (329) 583-586 doi:10.1180/minmag.1980.043.329.04
Localities for Cebollite
Showing 18 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.
Brazil | |
| Oliveira et al. (2020) |
Canada | |
| GOLD (1972) |
| Gold (1969) | |
Greenland | |
| Petersen et al. (1985) +1 other reference |
Lesotho | |
| Dana VIII +2 other references |
New Zealand | |
| Baker et al. (1980) |
| Railton et al. (1990) | |
Romania | |
| Pascal et al. (2001) |
Russia | |
| Pavel M. Kartashov (n.d.) |
| Chakhmouradian et al. (2002) |
| Keith Bell et al. (1996) +1 other reference |
South Africa | |
| Horst Windisch (2007) |
| rruff.geo.arizona.edu (n.d.) +1 other reference |
UK | |
| Tilley et al. (1931) |
USA | |
| [micromounts@yahoogroups.com] |
| Mineralogical Society of America - ... |
| Larsen (1942) +1 other reference |
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Iron Hill deposit, White Earth Mining District, Gunnison County, Colorado, USA