Reef Safe?

[ReeferNtraining]

I purchased this rock from a LFS and now I’m wondering if it’s even reef safe? I can see crystals in it, almost like a granite. Would that mean there are metals in it as well? Thoughts appreciated!

 

[EmdeReef]

Looks fine to me, but I can't see what concerns you. Do you know what type of rock this is?
The dark patches on the left piece could be some decaying matter.

 

[ReeferNtraining]

Looks fine to me, but I can't see what concerns you. Do you know what type of rock this is?
The dark patches on the left piece could be some decaying matter.

No, I don’t know what type it is. But it’s solid and dark. Not like typical lightweight porous rock. Seeing the crystals in it is what bothers me. Makes me wonder if there are not other minerals present.

 

[norfolkgarden]

How heavy is it?

Was it originally meant for a freshwater tank?

If it is not very porous or has limited surface area compared to the stuff we normally see it won't be nearly as effective in filtering.

 

[MikeyA]

I purchased this rock from a LFS and now I’m wondering if it’s even reef safe? I can see crystals in it, almost like a granite. Would that mean there are metals in it as well? Thoughts appreciated!

Break off a small piece and stick it on vinegar, that'll tell you if it's calcium carbonate base

 

[OutsideBrian]

Break off a small piece and stick it on vinegar, that'll tell you if it's calcium carbonate base

How? What does it do? I too have some pieces of rock I would like to test.

 

[MikeyA]

Basically anything of limestone/calcium carbonate base with a high pH will react to any acid medium. Just break off a small piece of rock and put it in a glass of distilled vinegar 5% preferably and see if it fizzles. Do it on the sink though it can get messy.