Azurite

$Cu_3(CO_3)_2(OH)_2$

  Family carbonates
  Crystal system monoclinic
  Color blue
  Streak color blue
  Cleavage 2 cleavages (1 perfect, 1 mediocre)
  Hardness 3,5 to 4
  Density 3,8

Explanations: → Here List of minerals: → Here