Petrified Ironwood
Petrified Ironwood is a variety of Ironwood found in Felwood.
They petrified during the War of the Ancients during the corruption that created Felwood. While they are darkened on the outside, inside they are opalized.
Felwood Opal is green, occasionally flecked with orange, clearly fel corrupted, and sturdier than typical opal. This opal has strange properties, both glowing and oozing slightly. Damaged trees that have this opal revealed can seem as though they have grotesque faces on them. (It is believed to be the satyrs that reside in the woods that have purposely disfigured them in this way.) It’s hard to say the trees are still alive, but they pulse with weak magic. (The opal once polished and properly treated will stop oozing and work as effective foci for fel magics.)