Anglesite


Anglesite

Infobox mineral
name = Anglesite
category = Sulfate mineral
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formula = PbSO4
molweight =
color = Colorless to white, commonly tintedgray; orange, yellow, green, blue, rarely violet
habit = Granular, banded, nodular to stalactitic
system = Orthorhombic - Dipyramidal (2/m 2/m 2/m)
twinning =
cleavage = [001] good, [210] distinct
fracture = Brittle to conchoidal
mohs = 2.5 - 3.0
luster = Adamantine crystals, dull when massive earthy
refractive = nα = 1.878 nβ = 1.883 nγ = 1.895
opticalprop = Biaxial (+)
birefringence =
pleochroism =
streak = White
gravity = 6.3
density =
melt =
fusibility = 1.5
diagnostic =
solubility =
diaphaneity = Transparent to translucent
other =
references = [http://rruff.geo.arizona.edu/doclib/hom/anglesite.pdf Mineral Handbook] [http://webmineral.com/data/Anglesite.shtml Webmineral data] [http://www.mindat.org/min-233.html Mindat]

Anglesite is a lead sulfate mineral, PbSO4. It occurs as an oxidation product of primary lead sulfide ore, galena. Anglesite occurs as prismatic orthorhombic crystals and earthy masses, and is isomorphous with barite and celestine. It has a high specific gravity of 6.3 due to its lead content, 74% by mass; its hardness is 2.5 - 3. Color is white, gray with pale yellow streaks. It may be dark gray if impure.

It was first recognized as a mineral species by William Withering in 1783, who discovered it in the Parys copper-mine in Anglesey; the name anglesite, from this locality, was given by F. S. Beudant in 1832. The crystals from Anglesey, which were formerly found abundantly on a matrix of dull limonite, are small in size and simple in form, being usually bounded by four faces of a prism and four faces of a dome; they are brownish-yellow in colour owing to a stain of limonite. Crystals from some other localities, notably from Monteponi in Sardinia, are transparent and colourless, possessed of a brilliant adamantine lustre, and usually modified by numerous bright faces. The variety of combinations and habits presented by the crystals is very extensive, nearly two hundred distinct forms being figured by V. von Lang in his monograph of the species; without measurement of the angles the crystals are frequently difficult to decipher. There are distinct cleavages parallel to the faces of the prism (110) and the basal plane (001), but these are not so well developed as in the isomorphous minerals barite and celestite.

Anglesite is a mineral of secondary origin, having been formed by the oxidation of galena in the upper parts of mineral lodes where these have been affected by weathering processes. At Monteponi the crystals encrust cavities in glistening granular galena; and from Leadhills, in Scotland, pseudomorphs of anglesite after galena are known. At most localities it is found as isolated crystals in the lead-bearing lodes, but at some places, in Australia and Mexico, it occurs as large masses, and is then mined as an ore of lead.

ee also

Lead(II) sulfate

References

*1911


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Look at other dictionaries:

  • Anglésite — Catégorie VII : sulfates, sélénates tellurates, chromates, molybdates, tungstates[1] Anglésite Touissit Maroc 5×4cm …   Wikipédia en Français

  • Anglesite — Anglésite Anglésite Général Synonymes sulfate de plomb (II) No CAS …   Wikipédia en Français

  • Anglesite — An gle*site, n. [From the Isle of Anglesea.] (Min.) A native sulphate of lead. It occurs in white or yellowish transparent, prismatic crystals. [1913 Webster] …   The Collaborative International Dictionary of English

  • anglesite — [aŋ′gəl sīt΄, aŋ′glə sīt΄] n. [after ANGLESEY, where it was discovered] a usually white, orthorhombic mineral, PbSO4, often found with galena; lead sulfate …   English World dictionary

  • anglesite — noun Etymology: French anglésite, from Anglesey Island, Wales Date: circa 1841 a mineral consisting of lead sulfate formed by the oxidation of galena …   New Collegiate Dictionary

  • anglesite — /ang geuhl suyt /, n. a mineral, lead sulfate, PbSO4, found in massive deposits and in colorless or variously tinted crystals: a minor ore of lead. [1830 40; named after ANGLESEY where it was first found; see ITE1] * * * ▪ mineral       naturally …   Universalium

  • anglesite — noun A crystalline mineral form of lead sulfate, PbSO, formed by the weathering of galena. A curious form of anglesite was noticed in a specimen from Durango, Iowa …   Wiktionary

  • anglesite — anglezitas statusas T sritis chemija apibrėžtis Mineralas. formulė Pb[SO₄] atitikmenys: angl. anglesite rus. англезит …   Chemijos terminų aiškinamasis žodynas

  • anglesite — ˈaŋgəlˌsīt, gləˌ noun ( s) Etymology: French anglesite, from Anglesey island, Wales, its locality + French ite : a common secondary mineral consisting of lead sulfate PbSO4 and formed by the oxidation of galena …   Useful english dictionary

  • anglesite —    A cave mineral PbSO4 [11] …   Lexicon of Cave and Karst Terminology