This is a Chrome Diopside specimen from the Merelani Hills in Tanzania. It is a calcium silicate based mineral that gets it's green color from the chromium inclusions in it. This piece features a natural termination and a nice lime green color all the way through. Nice translucency in certain parts of it.
This piece measures approximately 3.5cm x 2.4cm x 1.8cm and comes on an acrylic base measuring 3.2cm x 3.2cm