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| Leadhillite
was named in 1832 after the Type Locality, Susanna mine, Leadhills, Lanarkshire, Scotland.
| Discovered
in 1832; IMA
status:
Valid (pre-IMA; Grandfathered) |
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Chemistry
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Chemical
Formula: |
Pb4(SO4)(SO3)2(OH)2
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Lead
Sulfate Carbonate Hydroxide |
Molecular
Weight: |
1,078.90 gm
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Composition: |
Hydrogen |
0.19 % |
H |
1.67 % |
H2O |
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Lead |
78.82 % |
Pb |
88.68 % |
PbO2 |
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Carbon |
2.23 % |
C |
8.16 % |
CO2 |
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Sulfur |
2.97 % |
S |
7.42 % |
SO3 |
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Oxygen |
17.80 % |
O |
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100.00 % |
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105.93 % |
= TOTAL OXIDE |
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Classification
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Mineral
Classification: |
Carbonates
(Nitrates)
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Strunz 8th
Ed. ID:
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6/B.13-50
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Nickel-Strunz 10th
Ed. ID:
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5.BF.40
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5 : CARBONATES (NITRATES)
B : Carbonates with additional anions, without H2O
F : With (Cl), SO4, PO4, TeO3
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Related
to: |
Trimorphous with:
Macphersonite and Susannite. The monoclinic dimorph of Susannite.
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Varieties: |
None
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Synonyms: |
Lead sulphato-tricarbonate,
Maxite, ICSD 64807, PDF 35-617
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Crystal
Data
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Crystallography:
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Monoclinic - Prismatic
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Crystal
Habit:
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Crystals,
to 13 cm, are usually thin to thick tabular pseudohexagonal, with
hexagonal outline; several rhombohedral and pyramidal forms common; may be barrel-shaped,
or pseudorhombohedral {101} and {142}, also
prismatic parallel to [001], or equant, granular or massive. When [101] is
developed the faces may show striations, or be curved. Over 40 forms noted;
granular, massive.
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Twinning:
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On
{140}, {340}, {140}, very common, giving pseudohexagonal
groupings.
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Physical
Properties
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Cleavage: |
Perfect on {001} and easy.
Parting: translation gliding on {001}, as well as twin gliding with K1(340), σ2[140]; K2(34¯0), σ1[140].
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Fracture: |
Irregular/Uneven
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Tenacity:
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Brittle
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Moh's
Hardness: |
2.5
- 3.0
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Density:
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6.55 (g/cm3)
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Luminescence:
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Pale yellowish under Short
Wave UV |
Radioactivity:
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Not
Radioactive
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Thermal
Behaviour:
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Heating
results in a reversible transformation into Susannite. 2E is
approximately 20° (2V ~ 10°) at ambient temperature (for Na) and
decreases with increasing temperature. It becomes uniaxial negative at
about 125° and remains so at higher temperatures.
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Other: |
Soluble in nitric acid with effervescence, rendering a residue of lead sulphate. Exfoliates in hot water.
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Health
Warning: |
Caution:
Contains lead - always wash hands after handling. Avoid inhaling dust when
handling or breaking. Never lick or ingest. |
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Optical
Properties
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Color: |
Colorless,
white, gray, pale yellow, yellow, yellowish green, pale
green, pale bluish green, pale blue, brown; colorless
in transmitted light
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Transparency: |
Transparent
to translucent |
Luster: |
Resinous
to adamantine, pearly on {001} |
Refractive
Index: |
1.870
- 2.010 Biaxial ( - )
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Birefringence: |
0.140
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Dispersion: |
Strong; r < v |
Pleochroism: |
n/a |
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Occurances
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Geological
Setting: |
An
uncommon secondary mineral in the oxidation zone of
lead deposits. |
Common
Associations: |
Cerussite,
Anglesite, Lanarkite, Caledonite, Linarite (Leadhills,
Scotland); Cerussite, Caledonite, Linarite, Diaboleite,
Boleite, Wherryite, Paralaurionite, Brochantite (Mammoth-St.
Anthony mine, Arizona, USA).
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Common
Impurities: |
n/a
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Type
Locality: |
Susanna Mine (Glennery
Scar Vein; Susanna Vein [Scar Vein]; Portobello Vein; Humby Vein; Lead
Vein), Leadhills, South Lanarkshire, Strathclyde (Lanarkshire),
Scotland, UK |
Year
Discovered: |
1832
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View
mineral photos: |
Leadhillite
Mineral Photos and Locations |
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More
Information
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Mindat.org
Webmineral.com
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Leadhillite
is a lead sulfate carbonate closely related to and
trimorphous with Susannite and Macphersonite. Trimorphs are three different minerals that share the same chemistry, but have
different crystal structures.
In this case, Leadhillite is monoclinic, Susannite is trigonal and Macphersonite
is orthorhombic. Leadhillite is most often found as small to microscopic clear to white tabular
pseudohexagonal crystals but can also be found in larger sizes, to 13 cm, as
prismatic crystals and in various shades of yellow,
green, blue and brown. Leadhillite is quite soft with a Mohs
hardness of only 2.5 but a relatively high specific gravity of 6.26 to 6.55
and resinous
to adamantine luster. Leadhillite
was named in 1832 after the type locality, Susanna mine, Leadhills, Lanarkshire, Scotland.
Some of the best specimens have come from the Mammoth Mine, Tiger,
Arizona.
Attractive specimens are not rare but certainly not common but faceted gems
are very rare.
Distribution:
In Scotland, from Leadhills, Lanarkshire, and Wanlockhead,
Dumfriesshire; in the Drumruck mine, Kirkcudbrightshire.
In England, from Caldbeck Fells, Cumbria; at Penberthy
Croft, St. Hilary, and in the Greystone quarry, Levant,
Cornwall. From Bleiberg, Carinthia, Austria. In the
USA, from the Beer Cellar mine, Granby, Newton County,
Missouri; in the Tintic district, Juab County, Utah;
in Arizona, fine crystals from the Mammoth-St. Anthony
mine, Tiger, Pinal County, in the Rowley mine, near
Theba, Maricopa County, at the Grand Reef mine, Gila
County, and from Bisbee, Cochise County. In California,
at the Blue Bell claims, near Baker, San Bernardino
County; from the Searchlight district, Clark County,
and in the Chalk Mountain mine, Chalk Mountain district,
Churchill County, Nevada; from Leadville, Lake County,
Colorado. Very large crystals from Tsumeb, Namibia.
At Dundas, Tasmania, Australia. A few other localities
are known.
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