They are probably co-crystallized with it in the same way many crystals are with hydroxide - https://en.wikipedia.org/wiki/Water_of_crystallization#Other_solven

They are probably co-crystallized with it in the same way many crystals are with hydroxide - https://en.wikipedia.org/wiki/Water_of_crystallization#Other_solvents_of_crystallization https://en.wikipedia.org/wiki/Water_of_crystallization#Other... UV induced fluorescence would have been cooler tho