Crystal system Monoclinic
(repeating unit) Tl7Pb22As55S108|
Space group P21/c
|Crystal class Prismatic (2/m)
(same H-M symbol)|
Unit cell a = 37.62, b = 7.88, c = 20.07 [Å], β = 101.93° (approximated)
Heptasartorite is a very rare mineral with formula Tl7Pb22As55S108. It belongs to sartorite homologous series. It is related to other recently approved minerals of the series: enneasartorite and hendekasartorite. All three minerals come from a quarry in Lengenbach, Switzerland, which is famous of thallium minerals. Chemically similar minerals include edenharterite and hutchinsonite.