Charmarite-2H
A structural variant of Charmarite
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About Charmarite-2H
Charles and Marcelle Weber
Formula:
Mn2+4Al2(CO3)(OH)12 · 3H2O
Colour:
Brown, orange, pale blue, colorless
Lustre:
Vitreous
Hardness:
2½
Specific Gravity:
2.47
Crystal System:
Hexagonal
Name:
Named for Charles (1917-2003) and Marcelle (1918-2003) Weber, amateur mineralogists of Guilford, Connecticut, USA, who contributed extensively to the knowledge of Mt. St.-Hilaire and also found the mineral.
A polytype of Charmarite
The 2H polytype was originally described from Poudrette quarry (Demix quarry; Uni-Mix quarry; Desourdy quarry), Mont Saint-Hilaire, Rouville Co., Québec, Canada.
The 2H polytype was originally described from Poudrette quarry (Demix quarry; Uni-Mix quarry; Desourdy quarry), Mont Saint-Hilaire, Rouville Co., Québec, Canada.
Unique Identifiers
Mindat ID:
6862
Long-form identifier:
mindat:1:1:6862:4
GUID
(UUID V4):
(UUID V4):
53cf26e7-84ae-474b-b39d-822d8e12f2f3
Classification of Charmarite-2H
5.00.
5 : CARBONATES (NITRATES)
0 :
0 :
5 : CARBONATES (NITRATES)
0 :
0 :
Physical Properties of Charmarite-2H
Vitreous
Transparency:
Transparent
Colour:
Brown, orange, pale blue, colorless
Streak:
White
Hardness:
2½ on Mohs scale
Tenacity:
Brittle
Cleavage:
Perfect
{0001}
{0001}
Fracture:
Irregular/Uneven
Density:
2.47(1) g/cm3 (Measured) 2.50 g/cm3 (Calculated)
Optical Data of Charmarite-2H
Type:
Uniaxial (-)
RI values:
nω = 1.587(1) nε = 1.547(1)
Max Birefringence:
δ = 0.040
Image shows birefringence interference colour range (at 30µm thickness)
and does not take into account mineral colouration.
and does not take into account mineral colouration.
Surface Relief:
Low
Pleochroism:
Weak
Comments:
Weak pleochroism in pale-blue varieties. ω = colorless, ε = pale blue.
Strong pleochroism in the orange-brown varieties. ω = orange-brown, ε = very pale brown.
Strong pleochroism in the orange-brown varieties. ω = orange-brown, ε = very pale brown.
Chemistry of Charmarite-2H
Mindat Formula:
Mn2+4Al2(CO3)(OH)12 · 3H2O
Crystallography of Charmarite-2H
Crystal System:
Hexagonal
Class (H-M):
6 2 2 - Trapezohedral
Space Group:
P63 2 2
Setting:
P63 2 2
Cell Parameters:
a = 10.985(3) Å, c = 15.10(2) Å
Ratio:
a:c = 1 : 1.375
Unit Cell V:
1,578.00 ų (Calculated from Unit Cell)
Z:
4
Morphology:
Tabular hexagonal crystals, commonly stacked along [0001] to form pagoda like aggregates. Also as thin mica-like plates, sometimes forming star-shaped aggregates. Stacked tabular crystals can show parallel-growth features along {0001}. The most common forms observed are {0001} and {1010}.
Twinning:
None observed.
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 7.53 Å | (100) |
| 3.768 Å | (60) |
| 2.578 Å | (50) |
| 2.221 Å | (40) |
| 1.856 Å | (40) |
| 1.585 Å | (20) |
| 1.552 Å | (40) |
Comments:
Poudrette quarry, Mont Saint-Hilaire, Québec, Canada. The data are from the type description.
Synonyms of Charmarite-2H
Related Minerals - Strunz-mindat Grouping
| 5.00. | Charmarite-3T | Mn2+4Al2(CO3)(OH)12 · 3H2O |
Fluorescence of Charmarite-2H
Not fluorescent.
Other Information
Notes:
Attacked by 1:1 HCl and HNO3 with effervescence, and dissolve in 1:1 H2SO4 with effervescence.
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 Charmarite-2H
mindat.org URL:
https://www.mindat.org/min-6862.html
Please feel free to link to this page.
Please feel free to link to this page.
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References for Charmarite-2H
Reference List:
Chao, G. Y., Gault, R. A. (1997) Quintinite-2H, quintinite-3T, charmarite-2H, charmarite-3T and caresite-3T, a new group of carbonate minerals related to the hydrotalcite-manasseite group. The Canadian Mineralogist, 35 (6) 1541-1549
Zhitova, Elena S., Zolotarev, Andrey A., Kasatkin, Anatoly V., Sheveleva, Rezeda M., Krivovichev, Sergey V., Pekov, Igor V., Bocharov, Vladimir N. (2024) The crystal structure of charmarite – the first case of a 11 × 11 Å superstructure mesh in layered double hydroxides. Mineralogical Magazine, 1-29 doi:10.1180/mgm.2024.11
Localities for Charmarite-2H
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.
Canada | |
| Chao et al. (1997) |
Poudrette quarry, Mont Saint-Hilaire, La Vallée-du-Richelieu RCM, Montérégie, Québec, Canada