Any inert rock minerals with the same particle sizes will do the same thing.
Perlite floats to the surface with watering.
Pumice is very light, floats less and will lessen the weight of pots or density of garden beds.
Some people even use expanded styrofoam beads, ie from before compression to styro boxes, or bean bag pellets. These float out on the surface.
Aquarium gravel is similar particle sizes to pumice and as inert and non toxic. Zeolite has positive benefits in cycling nutrients.
Granite and Basalt gravels can contribute useful minerals.
Charcoal is similar density to pumice, but may be alkaline, affecting pH at high rates. Maybe ok in acid soils.
Fired clay beads or bits are also a possibility.
Graded pine bark, say 5mm to 10 mm is also in the particle size range.
Any gravels that contribute excess minerals ( ie limestone, high in Calcium Magnesium, raises pH ), or other Volcanics high in Zinc, Manganese etc might be avoided.