C Cure mastik

I am installing 2x4 natural stone to my kitchen backsplash. I was told it was ok to use mastik and not thinset. Is there a mastik that is modified and recommended for use with natural stone? Do I need to worry about it being modified or can I go without?

You were told by whom?
Use modified thinset mortar for stone or use any modified thinset mortar (white) and you'll be fine.

Those mastics are a little easier to use (on the front end) until the oils in them stain your stone then you'll be kicking yourself forever.

What C-Cure mastic were you considering? I didn't see one that works with stone. I don't have a problem using mastic for dry vertical areas such as a kitchen backsplash. But, you have to use one that is made for natural stone, otherwise it can stain as Bud mentioned.

I don't know why you're asking about modified. Thinsets can be modified, the term doesn't pertain to mastics.

Jaz