never heard of it. :\

Yes, but its not somthing you would want to leave sitting out in the open anyway. It gets on everything.

 

Well after a few months I can now confirm what happens to ferrofluid which is left out.

 

I left about 3ml on a petri dish (it was the end part that I just left so I could show others without having to pour out more every time).

 

Anyhow, after a few months of being in a non-air tight petri dish (the lid was on though).

 

Anyway, I've kinda got a almost solid black stuff.

 

It wont follow the magnet nor will it fall out of the dish if I turn it upside down. But the magnet is still attracted to it.

 

Conclusion being; the liquid the magnetic particles are suspended in has partially evaporated. It still has the same black colour, same smell, but it's hard and doesn't flow.