Can Anyone please help me Identify the type of Rocks in image?

[Sunnyme]

Hello everyone.

I have these white rocks on my campus and I wanted to know what is the name or type of these rocks. I have attached the image. I appreciate any help. Thank you.

 

[Ia.FurTrade]

Possibly limestone? Hard to tell without having them in hand...........

Iowa Dale

 

[Sunnyme]

Thank you for response. I tried to smash it and it didn't break. I tried concentrated HCL but it didn't fizz. This made me wonder if it is not limestone. I want to use it in my aquarium but scared that it will alter water chemistry.

 

[Ia.FurTrade]

Yeah, if I remember right, it should fizz in reaction to HCL.....Sorry I can't help you!

Iowa Dale

 

[DDancer]

Looks like a quartzite possibly metamorphic. Not an uncommon quarry stone. No real indications of iron or pyrites and it does not react to HCL so its stable enough to use as aquarium stone in my opinion.