My watch list  


CategorySulfosalt mineral
Chemical formulaTlAsS2
Colorred to carmine-red, lead grey
Crystal habitPrismatic tabular striated parallel to [001]
Crystal systemMonoclinic prismatic 2/m
Cleavage[100] perfect, [001] distinct
Mohs Scale hardness2.0 - 2.5
LusterSub metallic - adamantine
Refractive indexnα = 2.720
Optical PropertiesBiaxial (+)
PleochroismWeak; Y = purple-red; Z = orange-red
Specific gravity5.5288 - 5.5362
Other CharacteristicsTenacity: flexible, forming cleavage lamellae and fibers

Lorandite is a thallium arsenic sulfosalt with formula: TlAsS2. Though rare, it is the most common thallium bearing mineral. Lorandite occurs in low temperature hydrothermal associations. Occurs in gold and mercury ore deposits. Associated minerals include stibnite, realgar, orpiment, cinnabar, vrbaite, greigite, marcasite, pyrite, tetrahedrite, antimonian sphalerite, arsenic and barite.[1]

It was first discovered at Alshar, Republic of Macedonia in 1894 and named after Loránd Eötvös, physicist at the University of Budapest.

See also


  1. ^ a b Handbook of Mineralogy
  2. ^ Webmineral
  3. ^ Mindat
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Lorandite". A list of authors is available in Wikipedia.
Your browser is not current. Microsoft Internet Explorer 6.0 does not support some functions on Chemie.DE