I can Magic Eye. So if I can see the picture here, I will eventually be able to see bubbles on the dark side of the moon ... er ... the dark side of the moss agate? Okay, I'll try!
I thought I saw green on one which made me think "anti-blackie".
But if it's red and white without the extra color, then "anti-whitie" could work.
http://marbleconnection.com/topic/13092-anti-blackies/