Hello,
There is actually no such thing as a Super Crystal... I originally had called them Super Crystals before we found out that Specials and Mojaves are on the same allele. Which would make a Super Crystal impossible and now they are called Super Specials.
The link Tim posted shows a good explanation of the Epic gene. I will actually be posting a thread about my latest Epic clutch in the next couple minutes. Possibly have what might be a straight Epic which is the first time I have been excited about a single in awhile!
Tom Baker