Mimetite
Mimetite is a highly collectible mineral, found in the oxidation zone of lead deposits and
as an unusual associate a few other places. It generally forms slender, brightly coloured,
appealing crystals, and if present in a deposit, specimens tend to be attractive. It is
structurally identical to Pyromorphite; Pyromorphite is lead chloro-phosphate, and
Mimetite is lead chloro-arsenate.
The name Campylite is used for intermediates between Mimetite and
Pyromorphite, that often have barrel-shaped crystals. Campylite occurs in several mines
in Cumberland (England, Great Britain), where it forms exquisite caramel-coloured
crystals on a base of white Quartz and black Coronadite. Seemingly Mimetite rarely
transforms into other minerals, the only known pseudomorph to us is Beudantite
pseudomorph after Mimetite from Tsumeb (Namibia).
The mineral was named Mimetese by the French mineralogist Beudant in 1832 for
its ability to mimic Pyromorphite - both have the same crystal habit, range of colours,
and occur in the oxidation zone of lead deposits. Breithaupt changed the name into
Mimetesite in 1842, a name that is still commonly used in German literature, and finally
Haidinger in 1845 adopted the name Mimetite, that has stuck in English language
literature.
Our records indicate that Mimetite from a range of deposits occurs on specimens
that also carry one or more of the following minerals: Agardite-(La), Anglesite,
Aragonite, Barite, Brochantite, Calcite, Cassiterite, Cerussite, Chlorargyrite, Copper,
Coronadite, Cuprite, Dolomite, Duftite, Fluorite, Galena, Goethite, Linarite, Malachite,
Maricopaite, Mottramite, Phoenicochroite, Plumbogummite, Quartz, Smithsonite,
Sphalerite, Stannite, Stolzite, Tennantite, Tsumcorite, Willemite, Wolframite, Wulfenite,
and Zinnwaldite
Specimen Handling
Mimetite is for all practical purposes stable in a normal household environment. It is not
known to be harmed by light, changes in temperature in the normal comfort range, or
known to decompose. Mimetite specimens are often fragile and should be handled with
care. Mimetite is not appreciably soluble in water.
Bibliography
Bancroft, Peter. 1984. Gem & Crystal Treasures.
Cooper, Michael P. & Christopher J. Stanley. 1990. Minerals of the English
Lake District. Caldbeck Fells.
Gaines, Richard W., H. Catherine W. Skinner, Eugene E. Foord, Brian Mason,
Abraham Rosenzweig & Vandall T. King. 1997. Dana's new mineralogy:
the system of mineralogy of James Dwight Dana and Edward Salisbury Dana, 8th
ed.
Gebhard, Georg. 1991. Tsumeb, eine deutsch-afrikanische Geschichte.
Gebhard, Georg. 1999. Tsumeb, a unique mineral locality.
Hintze, Carl (ed.) 1921-1931. Handbuch der Mineralogie, vol. 1, section 4, part
1.
Noe-Nygaard, Arne. 1966. Mineralogi, 3rd ed.
Palache, Charles, Harry Berman & Clifford Frondel. 1951. The system of
mineralogy of James Dwight Dana and Edward Salisbury Dana, Yale University
1837-1892, 7th ed. Vol. 2.
Ramdohr, Paul & Hugo Strunz. 1980. Klockmann's Lehrbuch der
Mineralogie, 16th ed.
Roberts, Willard Lincoln, Thomas J. Campbell & George Robert Rapp jr.
1990. Encyclopedia of Minerals 2nd ed.
Sinkankas, John. 1964. Mineralogy.
This page is authored by Claus Hedegaard.
Mineraler