Current curve and way of making better clay is fun, but one of the thing that is capping hardly and is limited to the point in map is sand.
Possibility to crush a stone into sand (or just a one type of stone to limit excessive numbers) with like cutting quality in half when making sand out of stone would be great to work on your curios/glass/clay.
There are other possibilities to limit it > like only way to crush it would in in a windmill and the process will be really slow.
Your turn.