Found some rocks... w/ pics. Can you ID?

[mrcrazypants05]

We have a place in our back yard where a creek used to be. It has some pretty nice rocks. I didn't have much time so I grabbed some and took pics to see if anyone knows the type of rocks they are, because im dumb when it comes to rocks! If you guys think they are good I will wash them off... dry them... vinegar test them, and then boil them and soak them in dechlor water... is that they way to do it? Anyway here goes...

 

[Puriti]

YAY! ROCKS! first one kinda looks like a brick o.o

 

[greenmaji]

ironstone? and limestone, the two bigger ones look like..

 

[mrcrazypants05]

ah blast.. darn limestone... What is Ironstone? Is it safe?

 

[greenmaji]

actually nither look safe for reasons.. the iron stone.. if thats what it is.. is far too big even for a planted tank that you were trying to introduse it as a iron source.. the limestone will buffer your PH up and you have SA's.. see if you dont get a second oppinion but thats what I think you have..

 

[rubysoho]

to test if they will raise your pH, put a drop of vinegar on the rocks and see if it fizzles. If it does, then it will raise your pH.

 

[greenmaji]

muratic acid works better.. they sell it at ace or true value..

 

[Toirtis]

Possibly a creek-smoothed red slate or basalt (can't be sure of the colour there), the others look like some sort of aggregate.

 

[Guest]

i used the vinegar test on some shells i got from the beach and i got about 2-3 good shells that didn't fizz.. one of them was half of a conch shell and my cories have deemed it their new house.. all 6 will get up there and ive even caught a clown loach or two join in. Anyway i find i can always tell if its going to fizz from teh vinegar just by the texture.. if its smooth and shiny its usually safe, but if its rough and gritty then its usually going to fizz. HTH and defintly tell us how the vinegar test goes.