Anglesite is a
leadLead is a main-group element with symbol Pb and atomic number 82. Lead is a soft, malleable poor metal, also considered to be one of the heavy metals. Lead has a bluish-white color when freshly cut, but tarnishes to a dull grayish color when exposed to air...
sulfate mineralThe sulfate mineral class are those minerals which include the sulfate ion within their structure. The sulfate minerals occur commonly in primary evaporite depositional environments, as gangue minerals in hydrothermal veins and as secondary minerals in the oxidizing zone of sulfide mineral deposits...
, PbSO
4. It occurs as an oxidation product of primary lead sulfide ore,
galenaGalena is the natural mineral form of lead sulfide. It is the most important lead ore mineral.Galena is one of the most abundant and widely distributed sulfide minerals. It crystallizes in the cubic crystal system often showing octahedral forms...
. Anglesite occurs as prismatic orthorhombic crystals and earthy masses, and is isomorphous with
bariteBaryte, or barite, is a mineral consisting of barium sulfate. The baryte group consists of baryte, celestine, anglesite and anhydrite. Baryte itself is generally white or colorless, and is the main source of barium...
and celestine. It has a high specific gravity of 6.3 due to its
leadLead is a main-group element with symbol Pb and atomic number 82. Lead is a soft, malleable poor metal, also considered to be one of the heavy metals. Lead has a bluish-white color when freshly cut, but tarnishes to a dull grayish color when exposed to air...
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 WitheringWilliam Withering was an English botanist, geologist, chemist, physician and the discoverer of digitalis.-Introduction:...
in 1783, who discovered it in the Parys copper-mine in
AngleseyThe Isle of Anglesey , is an island and county off the northwest coast of Wales, with a predominantly Welsh-speaking population. It is connected to the mainland by two bridges spanning the Menai Strait: the original Menai Suspension Bridge , designed by Thomas Telford in 1826; and the newer...
; the name anglesite, from this locality, was given by
F. S. BeudantFrançois Sulpice Beudant , French mineralogist and geologist, was born in Paris.He was educated at the Ecole Polytechnique and Ecole Normale, and in 1811 was appointed professor of mathematics at the lycée of Avignon. Thence he was called, in 1813, to the lycée of Marseilles to fill the post of...
in 1832.
Anglesite is a
leadLead is a main-group element with symbol Pb and atomic number 82. Lead is a soft, malleable poor metal, also considered to be one of the heavy metals. Lead has a bluish-white color when freshly cut, but tarnishes to a dull grayish color when exposed to air...
sulfate mineralThe sulfate mineral class are those minerals which include the sulfate ion within their structure. The sulfate minerals occur commonly in primary evaporite depositional environments, as gangue minerals in hydrothermal veins and as secondary minerals in the oxidizing zone of sulfide mineral deposits...
, PbSO
4. It occurs as an oxidation product of primary lead sulfide ore,
galenaGalena is the natural mineral form of lead sulfide. It is the most important lead ore mineral.Galena is one of the most abundant and widely distributed sulfide minerals. It crystallizes in the cubic crystal system often showing octahedral forms...
. Anglesite occurs as prismatic orthorhombic crystals and earthy masses, and is isomorphous with
bariteBaryte, or barite, is a mineral consisting of barium sulfate. The baryte group consists of baryte, celestine, anglesite and anhydrite. Baryte itself is generally white or colorless, and is the main source of barium...
and celestine. It has a high specific gravity of 6.3 due to its
leadLead is a main-group element with symbol Pb and atomic number 82. Lead is a soft, malleable poor metal, also considered to be one of the heavy metals. Lead has a bluish-white color when freshly cut, but tarnishes to a dull grayish color when exposed to air...
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 WitheringWilliam Withering was an English botanist, geologist, chemist, physician and the discoverer of digitalis.-Introduction:...
in 1783, who discovered it in the Parys copper-mine in
AngleseyThe Isle of Anglesey , is an island and county off the northwest coast of Wales, with a predominantly Welsh-speaking population. It is connected to the mainland by two bridges spanning the Menai Strait: the original Menai Suspension Bridge , designed by Thomas Telford in 1826; and the newer...
; the name anglesite, from this locality, was given by
F. S. BeudantFrançois Sulpice Beudant , French mineralogist and geologist, was born in Paris.He was educated at the Ecole Polytechnique and Ecole Normale, and in 1811 was appointed professor of mathematics at the lycée of Avignon. Thence he was called, in 1813, to the lycée of Marseilles to fill the post of...
in 1832. The crystals from Anglesey, which were formerly found abundantly on a matrix of dull
limoniteLimonite is an ore consisting in a mixture of hydrated iron oxide-hydroxide of varying composition. The generic formula is frequently written as FeO·nH2O, although this is not entirely accurate as limonite often contains a varying amount of oxide compared to hydroxide.Together with...
, 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
SardiniaSardinia is the second-largest island in the Mediterranean Sea . The area of Sardinia is . The nearest land masses to the island are the French island of Corsica, the Italian Peninsula, Tunisia, and the Spanish Balearic Islands...
, 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
LeadhillsLeadhills is a village in South Lanarkshire, Scotland, 5¾ miles WSW of Elvanfoot. Population 835. It is the second highest village in Scotland after Wanlockhead, lying 395m above sea-level, near the source of Glengonnar Water, an affluent of the River Clyde...
, in
ScotlandScotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...
,
pseudomorphIn mineralogy, a pseudomorph is a mineral or mineral compound that appears in an untypical form , resulting from a substitution process in which the appearance and dimensions remain constant, but the original mineral is replaced by another...
s 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
AustraliaAustralia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the continental mainland , the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans...
and
MexicoThe United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
, it occurs as large masses, and is then mined as an
oreAn ore is a type of rock that contains minerals such as gemstones or metals that can be extracted through mining and refined for use. Samples of ore in the form of exceptionally beautiful crystals, exotic layering visible when sectioned or polished or metallic presentations such as large nuggets or...
of lead.