Your rocks appear to be quartz bearing nodules of some sort but it is very hard to give 100% positive identification without seeing the crystals and without knowing the specific gravity / density of the stones.
If a stone feel heavier than a similar sized quartz pebble, the stone is not quartz, it is likely to be a common mineral like barite, calcite, or dolomite in descending likelihood.
A quartz geode with significant hollow space will feel significantly lighter (10%+ lighter) than a similar sized quartz pebble. If the stone feels about the same weight as a similar sized quartz pebble, the stone is likely to be a form a quartz (agate, jasper, chalcedony) and it may or may not be a geode. Some geodes are solid.
Does the crystals inside look similar to this? (image of a tiny quartz geode)
The quartz geodes can have crystals of other minerals like barite, calcite, fluorite, and dolomite in it.
My best is: your stones are probably quartz and might tumble well. Take caution, if the stones are barite or calcite, the stones can be tumbled into nothing if you assume they are quartz.