Heck, even a 1:1 conversion rate would suffice, taking into account how easily it is to generate fire quanta with immolation/cremation.
My first idea for this was:
"Melt: Convert 1
into 1
each turn.
5
Fracture: generate 4
(5
upped)"
This was a 1:1 ratio with a pseudo speed up skill at a net loss for the unupped, but the poll indicated that the community preferred a rustler like mechanic so I changed it.
Is it too late to change it back since the voting has already started?
I thought of something, if you keep melting the poor iceberg, aren't you going to eventually melt it to nothing?
As a theme effect i suggest a cap on the use.
A cap on skill use per turn or total number of times the skill can be used at all?