Is Any Big Type Of Rock Ok For Pond-building?

[dreamermama]

Hi, I have a neighbor who has a bunch of large rocks that she wants to get rid of, free for the taking.

I don't know the rocks' history or what kind they are; I believe they were just in this neighbor's yard from a previous owner. I am hoping to build a pond in a couple of years, but could also use some of the rocks sooner in my garden. I'm wondering if they'll be suitable for a pond, and if anyone can tell me of any limitations they know of when it comes to the rocks you use when building a pond. I think my pond would be around 70-100 sqft of surface area, so it would have to line that perimeter plus some for extra designs/waterfall/whatever. I'm just beginning to research pond building so I am open to any tips.

 

[lil.guppy]

Depending on where you live try and pick some rocks up at the local creeks or rivers if your area allows it.
If you do intend on using these rocks, put them in some water and then test the water in 24 hours to see where its at. Im sure they are ok though. I use the regular slate garden center rocks for my aquarium and never had them tested or anything.
I LOVE 'PONDING' I used to put my breeding guppies out there in the spring and early summer to fatten them up.