Can I put the fern fossils in my fish tank?
I would not advise it. Aside from the pyrophyllite coating being in danger of rubbing off, the shale would most likely poison the fish. This is all conjecture of course, but I would not try it.
Can I display them outside?
Yes you can, but the exposure to weather will wear away the pyrophyllite coating at a faster rate. They tend to keep their whiteness for a couple years if left outside. I would suggest keeping it under some sort of cover(ie:against the house) if left outside.
Do you prep your fern fossil specimens?
No, they are as they come out of the ground. They can be sprayed with a fixative to protect the pyrophyllite mineral. We do not do this anymore because most of our customers prefer their fossils in a completely natural state. Some people use a clear satin or semi-gloss spray, or even hair spray! We leave that up to the buyer to decide whether to do that or not now.
We do suggest if spraying the fossils, do so in extremely light coatings.