This is what gallium does to aluminum

From NileRed Shorts.

Gallium looks a lot like mercury, except unlike mercury, it really likes sticking to glass.  It also has a very different and unique reaction, when it’s added to aluminum.  I’ve actually never tried this myself, and I think I’ll test it out on this aluminum bat.  

Nile talks about lab safety (Chemistry is Dangerous):

NileRed Beaker mugs:

■ NileRed: