Re: 'Crystal' deodorant bad for you???

Thank you for all that research and details.

What I also learn since then is that there are two types of rock deodorants. One who is made of ammonium alun, which is a synthetic deodorant made from aluminium salts and those are dangerous for our health according to articles I read. The other one is made with potassium alun which is natural (found in nature like you explained). You can't tell the difference between the two just by looking at it, but the natural one works better and is safer. We have to carefully read the labels when we buy the rock deodorants so that they are made from potassium alun instead of ammonium alun.