to be 100% honest, i'm not sure if the blue jewel is plastic or the real deal, but as i noted in the review they finally got the color of the jewel right. i'm not sure how you would tell if it is a real jewel or not, but it looks very accurate to me.
good luck with the decision -- as noted by other members, it's unlikely you will regret picking this one up, particularly if you are comfortable with it's large size.
cheers
deltatahoe