They could be powered by flint & iron. Only select recipes would be available in these Pulverizers.

Only select recipes would be available in these Pulverizers.

To be more specific, maybe have the following (by default):

• Stone-tier pulverizer can pulverize ores that can be broken with a wooden pickaxe or less at the cost of flint.
• Iron-tier pulverizer can pulverize ores that can be broken with an stone pickaxe or less at the cost of iron.
• Diamond-tier pulverizer can pulverize ores that can be broken with an iron pickaxe or less at the cost of diamonds.