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 Langenbach, Switzerland, which is famous for thallium minerals.
- Category: Sulfosalt
- Formula: Tl7Pb22As55S108
- Crystal system: Monoclinic
- Crystal class: Prismatic (2/m) (same H-M symbol)
- Luster: Metallic
- Colour: Grey
- Hardness: 3 – 3½ on the Mohs scale
- Member of: Sartorite Group
Heptasartorite comes from Lengenbach quarry in Switzerland, which is famous for thallium sulfosalts. Chemically similar minerals include edenharterite and hutchinsonite.