You can do some tests to be able to tell that your emerald is real. You can put your emerald into a glass pot or jar with water. If there is green light radiating from it, then it is real. Also, try putting the emerald on your eyes. If you feel a cool feeling, it is real. A fake emerald will warm up. Also trying putting a drop of water on the emerald. If it maintains its shape, it is real. If the drop spreads, it is fake.