I did some research on Rock Ivy today. Everything I've found points to it being Atlantic Ivy,also called Irish Ivy (hedera hibernica). I'm unable to confirm this 100% so maybe some of our members in Scotland can give some details. Atlantic Ivy is differant from English Ivy (hedera helix). Both species can be found at nurseries throughout the U.S.

Atlantic Ivy (hedera hibernica)



English Ivy (hedera helix)