I feel like Gemdust is one of those items that have no real use in the game, seeing as they are a sub-par curio. I get that its kind of intended to be a useless item, given that you get it from failing to carve a gem, but I also feel that since gemdust is an item that exists in the game (rather than gems breaking and not giving you anything), there should be some uses for it. I read online that gemdust can be used to make certain fabrics, so possibly a type of fabric and some unique clothes could be made using gemdust. Another idea that would be simpler is adding curios that use gemdust, similar to how cavedust is used for Petraglyphs and such. Also read online that gemdust is sometimes mixed with oil and water to make a lubricant, so that could be another idea. I'm sure other people have more ideas too.
Overall the point of this post is to say that there should be some more uses for gemdust, and its better to have an item that in the game that serves a purpose instead of something that just gets discarded.