Lanarkite

Lanarkit is a rarely occurring mineral from the mineral class " Sulfate ( and relatives ) ." It crystallizes in the monoclinic crystal system with the chemical composition Pb2 [O | SO4 ] and usually develops prismatic in the direction of the b axis () elongated crystals in greenish white, off-white, gray, yellow to pale yellow in color with white stroke color.

Special Features

Chemically Lanakit belongs to the lead sulfates. Its Mohs hardness is between 2 and 2.5 and its density is 6.92 g/cm3.

Under long-wave UV light and X-rays show some Lanarkite yellow fluorescence.

Etymology and history

Was first discovered Lanarkit in the south of the former county of Lanarkshire, specifically in the " Susanna Mine" at Leadhills.

This has been described in 1832 by François Sulpice mineral Beudant, who named it after its type locality.

Classification

In the now outdated but still in use 8th edition of the mineral classification by Strunz the Lanarkit to the mineral class of " sulfates, selenates, tellurates, chromates, molybdates, tungstates " and then to the Department of " water clear sulfates with foreign anions " belonged, where he with Grandreefit, Leadhillit, Macphersonit, Olsacherit, Pseudograndreefit and Susannite formed a distinct group.

The 9th edition used since 2001 and valid by the International Mineralogical Association (IMA ) of the Strunz'schen Mineral classification assigns the Lanarkit also in the class of " sulfates ( selenates, tellurates, chromates, molybdates and tungstates ) " and then in the Department of " Sulfate ( selenates, etc.) with other anions, without H2O" a. This division, however, is further divided according to the size of the cations involved, so that the mineral is "With only large cations " to find according to its composition in the subdivision, where it forms the unnamed group 7.BD.40 the only member.

The mainly common in English-speaking classification of minerals according to Dana assigns the Lanarkit in the class of " sulfates, chromates and molybdates " and there in the department of " water clear sulfates with hydroxyl or halogen" one. Here he is the only member of the unnamed group 30.02.01 within the sub-division of " water clear with (AB) 2XO4Zq sulfates with hydroxyl or halogen" to find.

Education and Locations

As a typical secondary mineral is Lanarkit preferentially forms in Bleierzlagerstätten. It is accompanied by various lead minerals such as galena, from which it can be formed by weathering also.

Overall, Lanarkit so far (as of 2011) are detected in about 80 localities, so including in New South Wales and South Australia in Australia; Baden- Württemberg, Lower Saxony and North Rhine -Westphalia in Germany; Salzburg, Styria and Tyrol in Austria; Bohemia in the Czech Republic; as well as Arizona, Missouri and Utah in the United States.

Crystal structure

Lanarkit crystallizes in the monoclinic space group C2 / m ( Raumgruppen-Nr. 12) with the lattice parameters a = 13.75 Å; b = 5.70 Å; c = 7.07 Å and 115.8 ° and β = 4 formula units per unit cell.