Vrbaite
Vrbaite (symbol: Vrb) is an opaque to subtranslucent brittle mineral with chemical formula Tl4Hg3Sb2As8S20 and pyramidal crystals. It is names after Czech mineralogist Karel Vrba. It is bluish white with red internal reflections and dark red in translucent thin fragments. It is classified in the class "sulfides and sulfosalts".[1][2]
Type locality: Allchar deposit, Ržanovo mine, Kavadarci Municipality, North Macedonia.[2][3]