I was pretty young at the time (read in the mid-90s) and don't remember much of it. It wasn't YA and I probably didn't understand a lot of the plot.
I think of it as "low fantasy"- I don't think there was magic in the world except for what the protagonist had, and even though he was a "sorcerer" he only drew power from a bottle of magic sand (or something like that) that he had mostly used up. One part that really stuck with me from the novel was that at one point he was imprisoned, unable to move at all, and he lived in his imagination for what felt like a large portion of the book.
The prison part stuck with me for a long time. He created an entire world in his mind, and IIRC it was even a story-within-the-story with him not realizing he was confined.
The "sand" part of it doesn't really stick out in my mind, and doesn't really sound right. What I remember more vividly was that different powers of spells used different amounts of the "grains" that were left. I think my memory is making them grains of sand but it could've been something else. I think he kept the bottle at the top of his tower and the climax, where he used the rest of his magic, took place there.
I rented it from the library either in 1993 or 1995-1997. The book looked fairly new. The cover was mostly white with I think a tower on it. Now that I think of it, the cover was uniquely minimalist for a fantasy book at that time. The title would have referenced magic in some way or little-me wouldn't have rented it.
Does that sound like something anyone else remembers?
