That’s an interesting tip! I have never tried this! Although it’s been a long time since I dropped rosin into a million pieces! I have seen rosin that was semi-melted from leaving it in a hot car, for example. This is still good to use!
There are some cool rosins at Superiorviolins.com !
Rockin Skull Violin Rosin – Guaranteed to bring out that ‘head bashing, hard rock’ sound you crave!*
Butterfly Violin Rosin – Made from the dust on the wings of magical butterflies!*