CHRYSOPHRAE PENDANT SIVER
This is a natural untreated stone  that has been cut roundel.
Also known as Australian jade
Strong vibrant colour.
The length from the neck is 220 mm

Chrysoprase, chrysophrase or chrysoprasus is a gemstone variety of chalcedony (a cryptocrystalline form of silica) that contains small quantities of nickel. Its color is normally apple-green, but varies to deep green. The darker varieties of chrysoprase are also referred to as prase. (However, the term prase is also used to describe chlorite-included quartz, and to a certain extent is a color-descriptor, rather than a rigorously defined mineral variety.)