wow. what equipment are you using?
me myself and shovel.
as I'm not lifting over 0.5m above the ground and I move them stones into a pile close by.
but well, that said, my arms are full of scratches. And I don't lift the heaviest of the heaviest ones, I throw only the stones that weight less then 20kg, lift up the stones around 40 -50 kg and roll the most heaviest ones.
Lifting them stones is hard as most of them are kinda edgy, sharp edges note that, sharp enough to make some nice wounds
+ the stones look de-formed, so I could call them rocks
+ some of them are heavier types of stone then others, there be light and heavy ones. so, the size you see says nothing of the weight...