Is this oxidation on rock?

[RedFrog211]

Wanted to add this rock to my tank, but after scrubbing and drying, I noticed this seemingly oxidized patch. Any way I can test it to make sure? Last thing I want is to put iron in the tank

 

[TankCandy]

I would let that rock soak in RO for a day or two then scrub to see if that blemish comes off. Where did you get the rock from?

 

[RedFrog211]

I would let that rock soak in RO for a day or two then scrub to see if that blemish comes off. Where did you get the rock from?

I got it from a LFS, but it did sit outside for about 2 months

 

[NeonRabbit221B]

I have seen similar coloration on my rock and haven't thought twice about it. I guess I am due for my first Insane Clown Posse test anyways

 

[TankCandy]

I would say you are fine and nothing to worry about.

I have seen similar coloration on my rock and haven't thought twice about it. I guess I am due for my first Insane Clown Posse test anyways

Same I have never done one either.

 

[Billdogg]

Looks pretty normal for reef rock to me. I wouldn't give it a second thought.

 

[Timfish]

What they said. Just FYI but iron is an essential element for photosythesis and also the main ingredient in GFO.

 

[RedFrog211]

I usually buy live rock, so I guess I’m just used to coralline covered rocks! Haha