Hello Guys!

I have a small bowl full of magnesium carbonate which you can get as "rock climbing" chalk from a sports store. Chances are you would find it at an outdoor sports store and for us in California we have REI. In ceramics, the magnesium can absorb a ton of water and when it dries, it shrinks a ton and will make "crater" or "beaded" textures. You could search ceramic crawl glaze and have an idea. A five pound bag is a lot bigger that you would expect because it truly is very light in weight compared to how much you can fit in a space. I find my blades that sit in the chalk bowl don't get water spots and since I use ASTRA Platinum quite often, aesthetically speaking, they turn a terrible looking color and I don't know if it what others call rusting. They tend to stay shinier and after I rinse a blade, I submerge it so it is completely covered.

Cheers everyone!