Yes, VERY carefully. Rough emeralds can be filled with oil or plastic to the extent that they are being held together by these foreign substances. If you trying cutting one which this has been done to it will often crumble and fall apart on the grinding wheel. With emeralds, you must start with solid materials to get a good gem from it. In addition emeralds can be color zoned so that the inside of the crystal is colorless and when you finish cutting, can end up with a very pale stone compared to what you started with. A cutter can't know until they finish cutting what the outcome will be unfortunately.