I would love to know the origin and stone on my brooch.

by Prue Bowen
(Westland, New Zealand)

I believe the pin is quite old as it belonged to my grandmother who died in the early 1950's. The stone is green, but not jade, I believe, as it seems 'glassy'. It is in need of a good clean but I am reluctant to do so until I know what the stone is. The brooch appears to be gold. Many thanks for your help.