chest are but dont leave anything on the floor

I had all the statues put them on the floor cause I couldnt get them on the darn shelf of the cabnet and came back to try again and boom they were gone... Ive looked in every chest in the place and cant find them so either some one came in and stole them.. (which I seriously doubt but would add a very interesting twist to the game) or they were eaten by the black hole of oops.
Same thing happened to me but with some replica swords.
Frostcrags chests are quite safe though. Also another question about Frostcrag do the ingredients grow back?
because I picked some stuff and it hasnt grown back yet, was wondering if maybe it takes longer to grow back than outside ingredients.