Ardaite occurs as 50 µm fine-grained aggregates of acicular crystals associated with galena, pyrostilpnite, anglesite, nadorite, and Cl-bearing robinsonite and semseyite, in the Madjarovo polymetallic ore deposit in Bulgaria.
Further, the municipality of Castro Verde is crossed by the Iberian Pyrite Belt, composed of a massive volcanogenic sulfide deposit (VMS) associated with the polymetallic flanks of volcanic cones in the form of pyrite, chalcopyrite, sphalerite, galena and cassiterite, that begins in Aljustrel, spreads through the lower Alentejo and extends into southern Spain.
The company was established in 1997 through the merger of eastern Kazakhstan’s three main nonferrous metals companies—Leninogorsk (now Ridder) Polymetallic complex, Ust-Kamenogorsk Lead and Zinc complex, and Zyryanovsk Lead Complex.
Philip Ridder (1759 - 1838) was a Russian explorer who discovered polymetallic ores in north-eastern Kazakhstan.