last edited: 11/11/17 number of photos: 18
Tanzanite is zoisite, Ca2Al3(SiO4)3(OH)
hardness: 6.5 to 7
Tanzanite- Linda Coe
tanzanite, faceted: A B C D E F G
tanzanite, faceted-tray of stones: A
tanzanite in jewelry
tanzanite rings: A* B* C* D* E F G H
tanzanite beads: A
Photos are copyright free for non-commercial educational uses.
Just credit photos to R.Weller/Cochise College.
Depending upon the orientation in which tanzanite is faceted,
it can either be a sapphire blue, an amethyst, or a grayish pale
green due to its pleochroism.
The intense blue color is the preferred orientation.
Vanadium is at least partially responsible for the color.
Brownish crystals of this material are heat treated to
produce the sought after purple-blue color.
Location of the source of gem quality tanzanite is
the Umba Valley
near the Usumburu Mountains, Tanzania near the Kenya border.