Board Thread:General Discussion/@comment-25555054-20150316025533/@comment-3035875-20150317100643

There seems to be some clues in Pearl's dialog.

"Is water just hydrogen and oxygen "mashed together"?" (Giant Woman (episode))

" We'll keep working on the dance for now, and who knows, in a few years... I wonder though if Steven's body is capable of fusion. Fusion merges the physical forms of gems, but Steven is half-human. He's organic" Alone Together

Notice how she compares fusion to chemisty. Maybe the dance triggers a chemical reaction of some sort.