Oval Turquoise Amazonite

Amazonite, also known as Amazonstone, is a green tectosilicate mineral, a variety of the potassium feldspar called microcline. Its chemical formula is KAlSi3O8, which is polymorphic to orthoclase.
Color: Green, blue-green
Crystal habit: Prismatic
Ultraviolet fluorescence: Weak; olive-green
Crystal system: Triclinic