I think it is...
I found another one on: http://munten.delcampe.be/page/item/id,168509409,var,Zeer-Oude-Gouden-Reaal-Karel-V-Karolus-DG-ROM-IMP-Z-HISP-RE-1542-56-WAARDE-2000euro-,language,D.html
(sorry it's in Dutch)
But I don't think it's a golden coin...
Anyone who got any idea of what this coin would be worth?