Bicolour tourmaline, October birthstone

An specimen of rough bi-colour tourmaline, clearly showing both pink and green in the same crystal!  Tourmaline comes in many colours and is an October birthstone (along with opal).  It is discreetly mounted on a black plastic pedestal.

5/8 inch (1.6 cm) wide, 5/16 inch (0.8 cm) deep and 1/2 inch (1.3 cm) tall.