This is a rare piece of mtorolite from Zimbabwe. Mtorolite is a chalcedony and a form of chrysoprase. The oxidized chrome content of mtorolite creates the vibrant green colour. The one side has been polished and displays a transluscent glassy surface with some sunken raw patches. The raw side shows off the growth habit, which is bubbly or grape-like. 
 
156gm
12 x 7 x 2cm