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Minerals K-O
Leadhillite
Name
Leadhillite
Chemistry
Pb4SO4(CO3)2(OH)2 , Lead Sulfate Carbonate Hydroxide.
Uses
As a mineral specimen
Color
Colorless, white, sky blue, pale sea green, yellow and gray. Pearly where cleaved
Hardness
2.5-3
Specific gravity
6.3-6.5
Crystals
Crystals are prismatic and tabular or platy crystals; also massive and granular. Pseudohexagonal and pseudorhombohedral twinned crystals are most common. Pseudomorphs after susannite are also seen. Leadhillite is also pseudomorphed by cerussite at times
Accompanied by:
Tsumcorite, malachite, silver, willemite, susannite, wulfenite, dioptase, chalcocite, galena, caledonite, anglesite, linarite and cerussite.
Similar to:
Mica when cleaved or takes on the form of cerussite.
Leadhillite is named after its aptly named type locality of Leadhills, Lanarkshire, Strathclyde, Scotland. It can be recognised by it's color, luster, environment of formation, density and an almost micaceous cleavage.
It forms in the oxidation zone of lead deposits as a secondary mineral, sometimes pseudomorphing other lead minerals and sometimes being pseudomorphed by other lead minerals.
A pseudomorph is a mineral that has replaced either the structure or chemistry of an earlier mineral, without distorting the outward shape of the original mineral; thereby producing a crystal that has the shape of one mineral, but is actually either chemically and/or structurally a different mineral.
Leadhillite is an attractive, brightly lustered and sometimes colorful mineral that is often associated with other rare and beautiful oxidation minerals. Its list of associated minerals reads like a collectors wishlist. Platy or tabular pseudohexagonal cyclic twinned crystals of leadhillite are the typical habit as well as prismatic crystals.
Leadhillite can be quite a popular collection mineral if it were only more available on the mineral markets.
Crystal habit, color, luster, environment of formation, density and an almost micaceous cleavage.