• ground materials such as sand, stone, ...
• Crops
• General Plants
• Trees
• Animal drops
• Mob Drops

These sulfurs should keep up the pattern used for minerals. That means "categories" are niters, only specific ones are sulfurs.
That would also solve #89

• To enable extensability, we need a KubeJS addon that allows to create new sulfur (and niter) items.
• That also means -> refactor sulfur item to not do niter too