Flamestone

Flamestone, and not Firestone as this is a company's name, was added for the Flamage biome. Then MCE had the idea of having it where you can have it burn nothing (Deactivated), burn mobs only, and burn players only.

There are multiple types of the block, only the normal one has an animated texture. The burn mobs has a slight red creeper face on it, the burn players has a slight Steve face on it, but you can only really see the eyes.

Obtaining
The normal "activated" flamestone is naturally generated in the flamage biome.

To get the other types, you can take the Eccentric Biomes Wrench and right click the normal "activated" flamestone. Upon doing so, it will turn into the deactivated type. When that one is right clicked with the wrench, it turns into the burn mobs only type, then into the burn players only type, then back into the activated.

Usage
Upon walking on the normal "activated" block, or the burn players only one, you will be set on fire. If you walk on the deactivated or burn mobs only block, you will not be set on fire, however any mob that walks on the burn mobs only block will be set on fire. If a mob walks on the deactivated or burn players only block, they will not be set on fire.

The normal "activated" flamestone is actually used in make the wrench.