1) Copper mineral 
Diaboleite is a blue-colored mineral with formula Pb2CuCl2(OH)4. It was discovered in England in 1923 and named diaboleite, from the Greek word διά and boleite, meaning `distinct from boleite`. The mineral has since been found in a number of countries. Diaboleite is deep blue in color and pale blue in transmitted light. The mineral occurs as .....