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Macquartite
A valid IMA mineral species
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About Macquartite
Formula:
Cu2Pb7(CrO4)4(SiO4)2(OH)2
Colour:
Orange cadmium
Hardness:
3½
Specific Gravity:
5.49
Crystal System:
Monoclinic
Name:
Named in 1980 by Sidney A. Williams and Marjorie Duggan in honor of Louis Charles Henri Macquart [5 December 1745 Reims, France - 12 July 1808 Paris, France], French medical doctor (l'école Centrale de Seine et Marne), chemist, and mineralogist. Macquart's books mostly contain medical information, but his Essais ou Recueil de mémoires sur plusieurs points de minéralogie with 580 pages + 7 plates in 1789 described the mines and minerals of Berosovsk and other topics. Macquart wrote a research article with Louis Vauquelin and they reported that the future "crocoite" contained lead peroxide, iron, and aluminum. Johan Bindheim re-analyzed the future "crocoite" and reported it contained molybdic acid, nickel, cobalt, iron, and copper. In 1798, Vauquelin re-analyzed the mineral, using the specimens supplied by Macquart and discovered they contained a new element, which Vauquelin named chromium. Macquartite was named in acknowledgement of Macquart's role in the chain leading to the discovery of chromium as a new element. Vaquelin's answer to the uncertainty of crocoite's true composition, unfortunately does not document Macquart's chemical participation in the discovery of chromium. Macquart was curator of the mineral collection at Fontainebleau, Seine-et-Marne.
This page provides mineralogical data about Macquartite.
Unique Identifiers
Mindat ID:
2514
Long-form identifier:
mindat:1:1:2514:6
IMA Classification of Macquartite
Approved
IMA Formula:
Cu2+2Pb2+7(Cr6+O4)4(SiO4)2(OH)2
Approval year:
1979
Classification of Macquartite
9.HH.05
9 : SILICATES (Germanates)
H : Unclassified silicates
H : With Pb
9 : SILICATES (Germanates)
H : Unclassified silicates
H : With Pb
Dana 7th ed.:
36.1.2.1
36.1.2.1
36 : COMPOUND CHROMATES
1 : Miscellaneous
36 : COMPOUND CHROMATES
1 : Miscellaneous
17.10.29
17 : Silicates Containing other Anions
10 : Silicates with sulphate, molybdate or tungstate
17 : Silicates Containing other Anions
10 : Silicates with sulphate, molybdate or tungstate
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 |
|---|---|---|
| Mcq | 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 Macquartite
Colour:
Orange cadmium
Streak:
Pale orange
Hardness:
3½ on Mohs scale
Cleavage:
Distinct/Good
Good on {100}
Good on {100}
Fracture:
Irregular/Uneven
Density:
5.49 g/cm3 (Measured) 5.58 g/cm3 (Calculated)
Optical Data of Macquartite
Type:
Biaxial (-)
RI values:
nα = 2.28 nβ = 2.31 nγ = 2.34
2V:
Measured: 85° , Calculated: 88°
Birefringence:
0.06
Max. Birefringence:
δ = 0.060
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:
Very 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.
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:
r > v strong
Optical Extinction:
Y = b; X ∧ c = 36°.
Chemistry of Macquartite
Mindat Formula:
Cu2Pb7(CrO4)4(SiO4)2(OH)2
Element Weights:
Crystallography of Macquartite
Crystal System:
Monoclinic
Cell Parameters:
a = 20.81 Å, b = 5.84 Å, c = 9.26 Å
β = 91.8°
β = 91.8°
Ratio:
a:b:c = 3.563 : 1 : 1.586
Unit Cell V:
1,124.82 ų (Calculated from Unit Cell)
Z:
4
Morphology:
Euhedral crystals in quartz
Comment:
Probably C2/m
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 10.43 Å | (20) |
| 7.019 Å | (10) |
| 4.822 Å | (90) |
| 4.628 Å | (90) |
| 4.202 Å | (10) |
| 3.557 Å | (10) |
| 3.467 Å | (30) |
| 3.405 Å | (30) |
| 3.211 Å | (10) |
| 3.156 Å | (100) |
| 3.090 Å | (60) |
| 2.925 Å | (50) |
| 2.818 Å | (10) |
| 2.768 Å | (50) |
| 2.707 Å | (10) |
| 2.607 Å | (5) |
| 2.561 Å | (5) |
| 2.525 Å | (30) |
| 2.469 Å | (20) |
| 2.320 Å | (40b) |
| 2.235 Å | (40b) |
| 2.135 Å | (20b) |
| 2.077 Å | (20) |
| 2.043 Å | (20) |
| 1.958 Å | (20) |
| 1.892 Å | (30) |
| 1.876 Å | (30) |
| 1.820 Å | (10b) |
| 1.779 Å | (10) |
| 1.756 Å | (10) |
| 1.728 Å | (10) |
| 1.700 Å | (5) |
| 1.673 Å | (10) |
| 1.578 Å | (30) |
Comments:
ICDD 33-466
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 7: Great Oxidation Event | <2.4 |
| 47a : [Near-surface hydration of prior minerals] | |
| 47e : [Vanadates, chromates, manganates] |
Type Occurrence of Macquartite
General Appearance of Type Material:
Crystals can reach 1 mm long
Place of Conservation of Type Material:
The Natural History Museum, London, England, 1980,542; University of Arizona, Tucson, Arizona; National Museum of Natural History, Washington, D.C., USA, R18726.
Associated Minerals at Type Locality:
Synonyms of Macquartite
Other Language Names for Macquartite
Common Associates
Associations Based on Photo Data:
| 14 photos of Macquartite associated with Quartz | SiO2 |
| 13 photos of Macquartite associated with Dioptase | CuSiO3 · H2O |
| 9 photos of Macquartite associated with Wulfenite | Pb(MoO4) |
| 5 photos of Macquartite associated with Willemite | Zn2SiO4 |
| 5 photos of Macquartite associated with Cerussite | PbCO3 |
| 5 photos of Macquartite associated with Fornacite | Pb2Cu(CrO4)(AsO4)(OH) |
| 4 photos of Macquartite associated with Fluorite | CaF2 |
| 1 photo of Macquartite associated with Hematite | Fe2O3 |
| 1 photo of Macquartite associated with Mimetite | Pb5(AsO4)3Cl |
Related Minerals - Strunz-mindat Grouping
| 9.HH.10 | Luddenite | Cu2Pb2Si5O14 · 4H2O |
| 9.HH.15 | Creaseyite | Pb2Cu2Fe3+2(Si4.67Al0.33)O15.33(OH)3 · H2O |
| 9.HH.20 | Plumbotsumite | Pb13(CO3)6(Si10O27) · 3H2O |
| 9.HH.25 | Molybdophyllite | Pb8Mg9[Si10O28(OH)8O2(CO3)3] · H2O |
Fluorescence of Macquartite
Not fluorescent in UV
Other Information
Notes:
Decomposed by concentrated 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 Macquartite
mindat.org URL:
https://www.mindat.org/min-2514.html
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Please feel free to link to this page.
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References for Macquartite
Localities for Macquartite
Showing 1 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.
USA (TL) | |
| Williams (1980) +2 other references |
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Mammoth-Saint Anthony Mine, St. Anthony deposit, Tiger, Mammoth Mining District, Pinal County, Arizona, USA