Talk:Opal Dragon/@comment-84.85.173.235-20121002233119/@comment-5085186-20121002234107

The Rainbow is the lowest possibility. For Gemstone dragons, the odds are estimated to be 3.5% in the breeding cave and 7% on the breeding Island.

Rainbow estimates at 1%, either location.

Olympus estimate at 10.5/18%

These are based on user testing and extrapolation. You can see the details for any dragon here: http://www.2084.org/dragonvale/breeding-sandbox/

Use the "Combo Finder" tab.