Mineral Species: Bournonite and Pyrite
Chemical Formula: CuPbSbS3
Chemical Name: Copper Lead Antimony Sulphide
Mineral Class: Sulphide
Mineral Notes: Bournonite is a popular collector mineral because of the striking silvery-grey crystals which have a strong tendency to form radiaiting (cogwheel-like) aggregates. For this reason Cornish miners, where particulalry striking specimens were once found, knew the mineral as Cogwheel Ore. Similarly, in Germany the mineral is known as Radelrz, or Wheel Ore.
Description: A very rich combo of Bournonite and Pyrite. Both form very good crystals. The Bournonite has the classic cog-wheel habit but this is best seen under magnification. The Pyrite crystals are highly distorted, many crystals having unusual pentagonal faces. The contrast between the two minerals is very attractive.
Location: Cavnic, Maramures, Romania.
