tanzanite
December's birthstone, tanzanite, is the gemstone name given to the blue to violet zoisite.
It is also known for its strong pleochroism, meaning that its color changes depending on the viewing angle.
Although it has a Mohs hardness of 6 to 7, it has a cleavage property that makes it vulnerable to impacts from certain directions, so when wearing it as jewelry, you should be careful not to subject it to strong impacts.
Karatz GemMagazine
" Tanzanite "
Karatz GemMagazine
" Tanzanite "