I dont believe they will allow you to take this on board. The only time that it is dangerous for a pregnant woman to fly is during solar flares when the radiation is up to 100x that of a chest x-ray. Check www.sec.noaa.gov for solar flare alerts. Other then that, I don't believe they will allow you to take crystallized ANYTHING on board for obvious reasons. Try looking for alternative protection via google.
I dont believe they will