Bayldonite
- named after its discoverer, the British physicist John Balydon
- Formula: PbCu3(AsO4)2(OH)2
- Space group: C2/c (No. 15)
- Crystal system: monoclinic
- Crystal class: 2/m
- Lattice parameters: a = 10.15 Å, b = 5.89 Å, c = 14.08 Å, β = 106.1°
Picture: Rob Lavinsky, iRocks.com – CC BY-SA 3.0
Crystal structure (click on the picture to download the VESTA file):
- Cu: blue, As: green, Pb: black, O: red, H: white
- elongated CuO6 octahedra
- AsO4 tetrahedra
- Pb surrounded by 7 oxygen atoms
The Fascination of Crystals and Symmetry 