Specific gravity: 5.4
Hardness: 3½ to 4
Paxite is a rare arsenide.
At the type locality, Černý Důl, Krkonoše Mountain, Czech Republic, paxite occurs in hydrothermal calcite veins cutting diopside hornfels lenses, in pyroxene gneiss and mica schist. It is probably a late-stage reaction product formed at the expense of novákite and arsenic below 130oC. Associated minerals include novákite, koutekite, arsenic, arsenolamprite, silver, löllingite, nickeline, chalcocite, skutterudite, bornite, chalcopyrite, tiemannite, clausthalite, uraninite, hematite and fluorite. The paxite is inter-grown with novákite, koutekite and especially with arsenic.
At Niederbeerbach, Germany, paxite is associated with lautite and kutinaite.
At Mohawk, Michigan, USA, paxite is associated with domeykite, algodonite and koutekite.