What Kind Of Rock?

[zxsixr]

Can anyone pls tell what kind of rock this is and would it be safe in my tank?
Thanks

 

[chicklette]

That is a nice rock. There is some kind of test with I THINK vinegar you can try. Someone else will come along to help.

 

[Matt_northants]

By the pic it looks like that there are veins of ore running through the rock so personally I wouldn't put it into your tank.

 

[Piltdownpaul]

You can pour vinegar on the rock-if it fizzes it isnt suitable as it probably has calcium in it which would harden your water and raise its ph above neutral towards an alkali.