Vesuvianite

$Ca_{10}(Mg,Fe)_2Al_4(SiO_4)_5 (Si_2O_7)_2(OH)_4$

  Family sorosilicates
  Crystal system quadratic
  Color green, yellow, brown, mauve, red, black, blue
  Streak color white to brown verdātre clair
  Cleavage 3 mediocre cleavages
  Hardness 6,5
  Density 3,4 to 3,5

Explanations: → Here List of minerals: → Here