We've been told that pre-loved Jazz is probably a Dutch Cross. When we found this out she immediately was nicknamed "Cross Dutch" as she's a grumpy girl if you touch her tummy or another guinea pig disturbs her when she's napping.
Obviously mine aren't purebreeds either but this is what a dutch piggy is defined to look like:
Round cheek markings not including the whiskers but near enough without touching
White blaze on the face should be wedge shaped being broadest at the base and tapering to a point between the ears
The saddle divides the body in two, the front half being white and the rear coloured
Ears a solid colour
Although I have no idea whos piggy actually looks like that! I'm happy with my two