Chrysolite
a green-colored orthorhombic magnesium-iron silicate of a vitreous luster, transparent or transclasses: Precious: Of a pale yellowishclasses: Precious: Of a pale yellowishgreen color and transparent, so as to be fit for jewelry. This is found in the to olive, or bottle-glass green; common in basalt and lavas, at times in large masses, having a rectangular outline.
The chrysolithus of Pliny was probably our topaz, and his topaz our Chrysolite.
It frequently changes color, becoming brownish or reddish-brown through the oxidation of the iron.