Not only was Merlin a fantastic wizard of amazing skills, he was also a phenomenal alchemist. He understood the basic properties of gold and ametyst, was quite amazing at mending the core of iron and basalt. He knew how to atune the alignment of the stars to the spessial properties of natural elements. How to make medallions and magic gems to change the inner ballance of stuff. he could make things crispy. A grand understanding of water vapour, wind husks, fire embers and earth soil. He could mix the essences of the bodiluss ballance, and harmonize with the tronelecs. It was once understood that the one spell he casted and one elixir he encoureged made certain that Morgana Le Fay never again caused havoch.