Stichtite-2H
A structural variant of Stichtite
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About Stichtite-2H
Formula:
Mg6(Cr,Al)2(CO3)(OH)16 · 4H2O
Colour:
Intense violet to rose-pink; violet to light rose-pink in transmitted light
Lustre:
Waxy, Pearly
Hardness:
1½ - 2
Specific Gravity:
2.05 - 2.15
Crystal System:
Hexagonal
Name:
Originally named barbertonite, for the type locality, Barberton District, Transvaal, South Africa. Later recognised as a polytype of stichtite and accordingly discredited (Mills et al., 2011, 2012).
First Recorded Locality:
A polytype of Stichtite
Originally named barbertonite. Recognised as a polytype of stichtite and accordingly discredited (Mills et al., 2011, 2012).
Originally named barbertonite. Recognised as a polytype of stichtite and accordingly discredited (Mills et al., 2011, 2012).
Unique Identifiers
Mindat ID:
514
Long-form identifier:
mindat:1:1:514:4
IMA Classification of Stichtite-2H
Discredited
Classification of Stichtite-2H
5.DA.45
5 : CARBONATES (NITRATES)
D : Carbonates with additional anions, with H2O
A : With medium-sized cations
5 : CARBONATES (NITRATES)
D : Carbonates with additional anions, with H2O
A : With medium-sized cations
16b.6.1.2
16b : HYDRATED CARBONATES CONTAINING HYDROXYL OR HALOGEN
6 : AmBn(XO3)pZqxH2O & with (m+n):p = 8:1
16b : HYDRATED CARBONATES CONTAINING HYDROXYL OR HALOGEN
6 : AmBn(XO3)pZq
Physical Properties of Stichtite-2H
Waxy, Pearly
Transparency:
Transparent
Colour:
Intense violet to rose-pink; violet to light rose-pink in transmitted light
Streak:
Very pale violet to white
Hardness:
1½ - 2 on Mohs scale
Tenacity:
Elastic
Cleavage:
Perfect
on {0001}
on {0001}
Density:
2.05 - 2.15 g/cm3 (Measured) 2.11 g/cm3 (Calculated)
Optical Data of Stichtite-2H
Type:
Uniaxial (-)
RI values:
nω = 1.557 nε = 1.529
Max. Birefringence:
δ = 0.028
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.
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.
Surface Relief:
Moderate
Pleochroism:
Weak
Comments:
O = dark rose-pink to violet
E = light rose-pink to violet
E = light rose-pink to violet
Chemistry of Stichtite-2H
Mindat Formula:
Mg6(Cr,Al)2(CO3)(OH)16 · 4H2O
Element Weights:
Crystallography of Stichtite-2H
Crystal System:
Hexagonal
Class (H-M):
6/mmm(6/m2/m2/m) - Dihexagonal Dipyramidal
Space Group:
P63/mmc
Cell Parameters:
a = 6.09689(6) Å, c = 15.6193(8) Å
Ratio:
a:c = 1 : 2.562
Unit Cell V:
502.82 ų (Calculated from Unit Cell)
Morphology:
Platy crystals, flattened on {0001}. Massive, in matted or contorted masses of fibers or plates; also as cross-fiber veinlets.
Comment:
Data of cotype specimen (from Mills et al., 2011); Z = 1/4.
First Recorded Occurrence of Stichtite-2H
General Appearance of First Recorded Material:
Platy crystals, fibrous matted masses and cross-fiber veinlets
Place of Conservation of First Recorded Material:
Harvard University, Cambridge, Massachusetts, USA (No. 92549)
Geological Setting of First Recorded Material:
Alteration products of chromite in serpentinite
Associated Minerals at First Recorded Locality:
Synonyms of Stichtite-2H
Other Language Names for Stichtite-2H
German:Barbertonit
Spanish:Barbertonita
Common Associates
Associations Based on Photo Data:
| 9 photos of Stichtite-2H associated with Serpentine Subgroup | D3[Si2O5](OH)4 |
| 6 photos of Stichtite-2H associated with Stichtite | Mg6Cr3+2(OH)16[CO3] · 4H2O |
| 4 photos of Stichtite-2H associated with Magnesiochromite | MgCr2O4 |
| 4 photos of Stichtite-2H associated with Aragonite | CaCO3 |
| 3 photos of Stichtite-2H associated with Lizardite | Mg3(Si2O5)(OH)4 |
| 3 photos of Stichtite-2H associated with Spinel Subgroup | A2+D3+2O4 |
| 1 photo of Stichtite-2H associated with Trevorite | Ni2+Fe3+2O4 |
| 1 photo of Stichtite-2H associated with Magnetite | Fe2+Fe3+2O4 |
| 1 photo of Stichtite-2H associated with Chrysotile | Mg3(Si2O5)(OH)4 |
| 1 photo of Stichtite-2H associated with 'Serpentinite' |
Related Minerals - Strunz-mindat Grouping
| 5.DA. | Alexkhomyakovite | K6(Ca2Na)(CO3)5Cl · 6H2O |
| 5.DA. | Amoraite | Ca12Al6(OH)36(CO3)2(SO3) · 15H2O |
| 5.DA.05 | Dypingite | Mg5(CO3)4(OH)2 · 5H2O |
| 5.DA.05 | 'UM1986-10-CO:ClHMgMnZn (also called Mineral F, Dunn, 1995)' | Mg5(Zn,Mn)3(CO3)2(OH,Cl)12 · H2O |
| 5.DA.05 | 'UM1987-01-CO:HMgS' | Mg4(CO3)2(OH)4 · 6H2O ? |
| 5.DA.05 | Giorgiosite | Mg5(CO3)4(OH)2 · 5-6H2O |
| 5.DA.05 | Hydromagnesite | Mg5(CO3)4(OH)2 · 4H2O |
| 5.DA.05 | Widgiemoolthalite | Ni5(CO3)4(OH)2 · 5H2O |
| 5.DA.10 | Artinite | Mg2(CO3)(OH)2 · 3H2O |
| 5.DA.10 | Chlorartinite | Mg2(CO3)(OH)Cl · 2H2O |
| 5.DA.10 | Indigirite | Mg2Al2(CO3)4(OH)2 · 15H2O |
| 5.DA.15 | Zaratite | Ni3(CO3)(OH)4 · 4H2O ? |
| 5.DA.15 | Otwayite | Ni2(CO3)(OH)2 · H2O |
| 5.DA.20 | Kambaldaite | NaNi4(CO3)3(OH)3 · 3H2O |
| 5.DA.25 | Callaghanite | Cu2Mg2(CO3)(OH)6 · 2H2O |
| 5.DA.30 | Claraite | (Cu,Zn)15(CO3)4(AsO4)2(SO4)(OH)14 · 7H2O |
| 5.DA.35 | Hydroscarbroite | Al14(CO3)3(OH)36 · nH2O |
| 5.DA.35 | Scarbroite | Al5(CO3)(OH)13 · 5H2O |
| 5.DA.40 | Karchevskyite | Mg18Al9(OH)54Sr2(CO3)9(H2O)6(H3O)5 |
| 5.DA.40 | 'UM1987-05-OH:AlCMg' | Mg4Al2(OH)12(CO3,SO4) · 3H2O |
| 5.DA.40 | Quintinite | Mg4Al2(OH)12(CO3) · 3H2O |
| 5.DA.40 | Charmarite | Mn2+4Al2(OH)12[CO3] · 3H2O |
| 5.DA.40 | Caresite | Fe2+4Al2(OH)12[CO3] · 3H2O |
| 5.DA.45 | 'Hydrotalcite-2H' | Mg6Al2(CO3)(OH)16 · 4H2O |
| 5.DA.45 | Brugnatellite | Mg6Fe3+(CO3)(OH)13 · 4H2O |
| 5.DA.45 | Zaccagnaite | Zn4Al2(OH)12[CO3] · 3H2O |
| 5.DA.45 | 'Pyroaurite-2H' | Mg6Fe3+2(OH)16(CO3) · 4H2O |
| 5.DA.45 | Liudongshengite | Zn4Cr2(OH)12(CO3) · 3H2O |
| 5.DA.45 | Chlormagaluminite | Mg4Al2(OH)12Cl2 · 3H2O |
| 5.DA.50 | Pyroaurite | Mg6Fe3+2(OH)16[CO3] · 4H2O |
| 5.DA.50 | Takovite | Ni6Al2(OH)16[CO3] · 4H2O |
| 5.DA.50 | Reevesite | Ni6Fe3+2(OH)16(CO3) · 4H2O |
| 5.DA.50 | Kaznakhtite | Ni6Co3+2(CO3)(OH)16 · 4H2O |
| 5.DA.50 | Comblainite | Ni4Co2(OH)12[CO3] · 3H2O |
| 5.DA.50 | Marioantofilliite | [Cu4Al2(OH)12](CO3) · 3H2O |
| 5.DA.50 | Hydrotalcite | Mg6Al2(CO3)(OH)16 · 4H2O |
| 5.DA.50 | Stichtite | Mg6Cr3+2(OH)16[CO3] · 4H2O |
| 5.DA.50 | Desautelsite | Mg6Mn3+2(OH)16[CO3] · 4H2O |
| 5.DA.55 | Coalingite | Mg10Fe3+2(OH)24[CO3] · 2H2O |
| 5.DA.55 | Akopovaite | Al4Li2(OH)12(CO3)(H2O)3 |
| 5.DA.60 | Šlikite | Zn2Mg(CO3)2(OH)2 · 4H2O |
| 5.DA.65 | Marklite | Cu5(CO3)2(OH)6 · 6H2O |
Other Information
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 Stichtite-2H
mindat.org URL:
https://www.mindat.org/min-514.html
Please feel free to link to this page.
Please feel free to link to this page.
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References for Stichtite-2H
Reference List:
Read, H. H., Dixon, B. E. (1933) On stichtite from Cunningsburgh, Shetland Islands. Mineralogical Magazine and Journal of the Mineralogical Society, 23 (140) 309-316 doi:10.1180/minmag.1933.023.140.03
Frondel, Clifford (1941) Constitution and polymorphism of the pyroaurite and sjögrenite groups. American Mineralogist, 26 (5) 295-315
Taylor, H. F. W. (1973) Crystal structures of some double hydroxide minerals. Mineralogical Magazine, 39 (304). 377-389 doi:10.1180/minmag.1973.039.304.01
Localities for Stichtite-2H
Showing 7 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.
Australia | |
| R Bottrill |
Czech Republic | |
| Ulrych |
New Zealand | |
| Railton et al. (1990) |
South Africa (FRL) | |
| Am Min 26 (1941) |
| www.johnbetts-fineminerals.com (2021) +2 other references | |
| Rocks & Min.: 21:275. | |
UK | |
| Anthony (1997) |
Nevada Creek, North Dundas, Zeehan mining district, West Coast municipality, Tasmania, Australia