Largest uncut emerald

This record is for the largest uncut emerald.
This record is to be attempted by an individual or a team.
This record is measured in carats (ca) to the nearest 0.01 carats; with the equivalent measurement also given in grams (g).
For the purposes of this record, Emerald is a variety of the mineral Beryl that is coloured green due to trace amounts of chromium.