When I had shaved today, I took a closer look at the alum stone/bar, and thought I could try to take a macro of it. I added some blue light from below.
Not a very exiting picture, but just an idea I got.
A bit of information on what this is:
An Alum Block is a crystal-like stone in the shape of a miniature bar of soap, also known as an alum stone or alum crystal, a mineral block made from potassium alum, a naturally occurring mineral and composite known for its antiseptic and astringent properties.
Historically used by the ancient Egyptians, potassium alum was used more than 4,000 years ago for its antiseptic and healing properties and to cool and revitalize the skin.
Available in different shapes and sizes, such as an alum bar or crystal, there are convenient travel-size alum sticks for precise application.
The alum bar today is utilized as a wet shaving essential in the post-shave process to cool and refresh the skin after shaving wetted with water and gently rubbed over the shaved area to minimize redness and soothe irritation, limit the appearance of razor bumps, fight razor burn, and heal minor nicks and cuts.
Because of their antibacterial properties, alum blocks can even tighten pores, kill surface bacteria, and reduce pimples and acne.
