The color is definitely right. The size would be quite large for an emerald. Check for scratches to ensure it is not glass (glass has a much lower hardness than beryl and will show signs of wear.) Also does it have natural-looking cloudy inclusions? That would be a good indicator for emerald as emerald is rarely flawless.
My suggestion would be to take it to jeweler and get it professionally appraised, since there is no way to make a true ID just by seeing it - let alone seeing it only in pictures.