PRR 128.
Dimensions at widest points approximately 110 mm x 110 mm x 90 mm thick.
Weighs 1,205 grams.
Prase is a chrome-rich chert. Also called Dragon Stone.
The green colour usually derives from minor mineral content, most commonly the green chromiferous muscovite mica, fuchsite.
There are numerous Prase deposits in the Pilbara region of Western Australia.