ロケットから出たガスなどが小さな氷になって...
The gases that came from the rocket turned into small ice (crystals) and ...
Is this sentence complete? I would expect to see "small ice crystals", "small pieces of ice" etc, rather than just "small ice".
If this is fine can I extend it to other quantities that, in English, would be regarded as uncountable, e.g. can I say 大きな水 to mean large droplets of water, or even large amounts of water. Depending on the context I can imagine this referring to cloud formation or contrasting the size of a lake with the size of an ocean.