Crushed oyster shells need more crushing

[Quailwhatdoyaknow]

So recently I picked up some crushed oyster shells for my birds. Some of the pieces are too large and they don’t even attempt to eat them. I have tried breaking up the larger pieces with hammer and it does work but I never imagined they were that hard. Would a mortar and pestle but a good idea? I don’t think my food processor could handle them. I will be looking for the crushed oyster shells that are pretty much a powder to replace the ones I have but I’d like to use what I have up first.

 

[pac]

I've been giving this some thought, too. For the future. I have oyster shells from when I had chickens, but I don't recall the size.
I was thinking maybe put some in a plastic ziplock and use a rolling pin. I'd hate to buy a mortar and pestle just for breaking up oyster shells. I've gotten along without one so far.

 

[Nabiki]

I have a stainless steel mortar and pestle that seems to work fairly well. I think that it's going to be work no matter what method you use, though.

 

[PrettyBirdRocky]

Ziplock bags and hammer?

 

[Quailwhatdoyaknow]

Ziplock bags and hammer?

This is my current method

 

[PrettyBirdRocky]

This is my current method

I *cough* once *cough* tried my blender... Fam won't let me live it down. It worked ... Lol but scratched up container. Still works to this day lol

 

[GuineaMania]

Flaked oyster shells might be less hard?

 

[FatherFalcon]

I put a hand full on the side walk then I use the top side of this back and forward grind to size...