Sulfosalt, plagionite group
Specific gravity: 6.08
Colour: Steel-grey to black
Semseyite occurs in hydrothermal veins formed at moderate temperature,
associated with sorbyite, jamesonite,
bournonite, arsenopyrite and
At the Van Silver Property, Vancouver Mining Division, British Columbia, Canada, semseyite has been observd in co-deposition with fizelyite and on calcite. More frequently it appears on quartz, pyrite and sphalerite.
At Yaogangxian, Hunan, China, semseyite is associated with freibergite, and stannite.
Common impurities: Ag,Cu,Fe