last edited: 11/15/17 number of photos: 6
Tourmaline is Na(Li,Al)3Al6(BO3)3Si6O18(OH)4
hardness: 7 to 7.5
tourmaline as a mineral
tourmaline cabochons, mixed colors: A B
tourmaline in jewelry
pink tourmaline pendant: A*
Photos are copyright free for non-commercial educational uses.
Just credit photos to R.Weller/Cochise College.