is it safe to store these with other coins?

[Nerosmyfavorite68]

I ask, out of an abundance of caution.  I had to hurriedly put away the few coins that were out, because the Spectrum tech was coming over (better safe than sorry).  The coins are in flips.  The storage place is a coin box.  I had been slow to put these two away.

The raised crud on the Heraclius is stable verdigris.  The green in the fields was the gray area.  I put it between some silver coins.  The encrustations on the silver coin looks to be verdigris.  How did a silver coin manage to get verdigris?  The Heraclius is unchanged since I got it.

Can BD travel between coins in flips?  Is there some sort of gas it gives off?

 

[Nerosmyfavorite68]

I'm a bit more concerned about storing this one.  I looked at the crud on the m, and it's maroon and dark green.  There have been no changes in about 6 months.  I stacked it on top of a slab.

[Nerosmyfavorite68]

Any opinions on whether I should store these three separately?

[expat]

None of the three appear to have BD. If you have doubts, then store them away from others. Off gassing from plastic, paper etc. is what causes toning (nice or ugly) along with moisture and heat in the air. Silver can certainly tone in various colours but it will not have BD.