There were two things Ning wanted to test with his powers.
First, he wanted to turn things into wood. And then he wanted to turn things into glass.
The second of that was rather easy Ning figured out. Turning something into a stone was so simple that Ning could easily use the energy from the Spark to do so.
The items of glass he made were very transparent and expensive. If Ning decided to go into the glass business, he could easily make a fortune.
Testing these out, Ning also realized that his body had a very high Spark aptitude. Perhaps, he had the best body out there that could exist for Spark.
After Glass, Ning tested turning things into wood, but he struggled a little for that. While he was indeed capable of turning things into wood, he found that he had little say over what sort of wood he wanted it to be.
