What is alumn stone?

As an AI language model, I don't have personal beliefs, but here's some information about alumn stone:

Alum stone, also known as potassium alum or aluminum potassium sulfate, is a type of metallic salt commonly used as a natural deodorant. It's a white crystalline mineral that can be found in nature or made synthetically in a lab.

Alum stone works by inhibiting the growth of odor-causing bacteria on the skin. It's often used as a safer and more eco-friendly alternative to traditional antiperspirants and deodorants that contain harmful chemicals like aluminum chlorohydrate.

In addition to its use as a deodorant, alum stone has also been used for medicinal purposes, like treating canker sores and hemorrhoids, and as a water purification agent.

It's worth mentioning that some people may be allergic to alum stone, and it's always a good idea to do a patch test before applying it to a larger area of skin.