Green highlighter like pattern/growth on rock

[tunicata]

Hi,
I have a bunch of rocks left over from various projects.
Unfortunately, there is a bunch of green...stuff on them.

The green isn't furry or anything. No specific texture that I can express. It is akin to ...a highlighter. It's as if some one has taken a marker and danced upon the face of the rock.

Background:
These rocks have been locked in a thick and dark colored plastic box for months. No light and only the water entrapped within the crevices of the rock.

Any ideas? The rocks were algae free (visual inspection) when put into the box.

Also, this stuff appears on all of the rocks regardless of placement. So, the ones that were sitting in an empty tank for months also developed this. However, these had access to ambient light and had a lower occurence of the green highlighting!

I suppose there could be some chemical energy at work but probably not under these conditions.

How do I get rid of it. I may start up a nano tank (still in box!!!) this spring.

 

[jaa1456]

So they are not in any kind of water at all and just sitting in the plastic? Sounds like to me it is from algae. I had about 80lbs of live rock that I removed from a tank and needed to let them dry out and the green glow was on there for 3 years. They were in a rubbermaid container and were also left in the sun for about a week. I used some of them in my new tank and the lights made it glow more. Know they are covered in other algaes and you cant see that green at all. I would let those rocks fully dry out before using them and then rinse them. They probably contain a lot of die off from being in a dark container with very little water.