There are a few sure signs that your emerald jewellery is real. First is from the signature green colour, which can range in hue from yellow-green to blue-green. Most emeralds are also not completely clear but instead have inclusions known as "jardin" that add to their beauty and uniqueness. Additionally, when held up to the light, a genuine emerald will lightly shine, but it won't exhibit the sparkling rainbow flashes known as "fire." If you want to be certain that your fine jewellery has real emeralds, then all you have to do is purchase from an established and reputable jeweller like Blue Nile.