Quintinite-3T
A structural variant of Quintinite
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About Quintinite-3T
Formula:
Mg4Al2(OH)12CO3 · 4H2O
Colour:
Bright yellow to pale yellow
Lustre:
Vitreous
Hardness:
2
Specific Gravity:
2.14
Crystal System:
Trigonal
Name:
Named after Quintin Wight (b. 1935), of Ottawa, Ontario, Canada, significant contributor to mineral studies at Mont Saint-Hilaire, and author of The Complete Book of Micromounting (1993).
A polytype of Quintinite
The 3T polytype was originally described from Poudrette quarry (Demix quarry; Uni-Mix quarry; Desourdy quarry), Mont Saint-Hilaire, Rouville Co., Québec, Canada.
The 3T 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:
7266
Long-form identifier:
mindat:1:1:7266:9
GUID
(UUID V4):
(UUID V4):
56639172-1cfa-4c76-ad46-b07b4a84a478
Physical Properties of Quintinite-3T
Vitreous
Transparency:
Transparent
Colour:
Bright yellow to pale yellow
Streak:
White
Hardness:
2 on Mohs scale
Tenacity:
Brittle
Cleavage:
Perfect
{0001}
{0001}
Fracture:
Irregular/Uneven
Density:
2.14(1) g/cm3 (Measured) 2.14 g/cm3 (Calculated)
Optical Data of Quintinite-3T
Type:
Uniaxial (+/-)
RI values:
nω = 1.533(1) nε = 1.533
Max Birefringence:
δ = 0.000 - 0.533
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:
Moderate
Comments:
Most crystals are non-pleochroic, however,one with a Mg:Fe ratio of ~1 is pleochroic, with O = dark green, E = light green.
Chemistry of Quintinite-3T
Mindat Formula:
Mg4Al2(OH)12CO3 · 4H2O
Crystallography of Quintinite-3T
Crystal System:
Trigonal
Class (H-M):
3 2 - Trapezohedral
Cell Parameters:
a = 10.571 Å, c = 22.71 Å
Ratio:
a:c = 1 : 2.148
Unit Cell V:
2,197.76 ų (Calculated from Unit Cell)
Z:
6
Morphology:
Hexagonal tabular crystals on {0001}, commonly forming rosettes. Common forms are {0001} and {1010}.
Twinning:
None observed.
Comment:
Space group P3112 or P3212.
Epitaxial Relationships of Quintinite-3T
Epitaxial Minerals:
Donnayite-(Y) | NaCaSr3Y(CO3)6 · 3H2O |
Epitaxy Comments:
Quintinite-3T on donnayite-(Y). See Chao and Gault (1997).
X-Ray Powder Diffraction
Powder Diffraction Data:
d-spacing | Intensity |
---|---|
7.57 Å | (100) |
3.778 Å | (90) |
2.570 Å | (40) |
2.281 Å | (40) |
1.932 Å | (40) |
1.524 Å | (20) |
1.493 Å | (20) |
Comments:
Poudrette quarry, Mont Saint-Hilaire, Québec, Canada. The data are from Chao and Gault (1997).
Synonyms of Quintinite-3T
Fluorescence of Quintinite-3T
Not fluorescent
Other Information
Notes:
Attacked slightly by 1:1 HCl, strongly by HNO3, and dissolves in 1:1 H2SO4.
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 Quintinite-3T
mindat.org URL:
https://www.mindat.org/min-7266.html
Please feel free to link to this page.
Please feel free to link to this page.
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References for Quintinite-3T
Localities for Quintinite-3T
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).
Struck out - Mineral was erroneously reported from this locality.
Faded * - Never found at this locality but inferred to have existed at some point in the past (e.g. from pseudomorphs).
All localities listed without proper references should be considered as questionable.
All localities listed without proper references should be considered as questionable.
Canada | |
| American Mineralogist: 83: 1347. +1 other reference |
Poudrette quarry, Mont Saint-Hilaire, La Vallée-du-Richelieu RCM, Montérégie, Québec, Canada