Alien matter in DF

Does anyone use alien matter in your DF campaign? What I mean by this is having the bodies of Elder Things composed of something else besides normal matter. It would seem that if some being from another reality came into ours, it would likely be composed of material far different from ours. Mayne the way it interacts with our reality could be different? Another example might be spirit matter that does not interact with normal matter unless it is provided with some sort of magical or spiritual power. Just curious if anyone has any interesting ideas about this.



I know adamantine and meteoric might also be considered alien matter but I am interested in newer stuff especially Elder Things and spirits. Thanks.

Alien matter in DF