The chemical inside is (most commonly) sodium silicate. It's the "active ingredient" in there. It is synthetically fabricated so that a lot of surface area is exposed in the granules. That's so it...
Silica gel is a granular, vitreous, highly porous form of silica and is made synthetically from sodium silicate.
It starts out as a gel when it's first synthesized, then it's left to dry.
quartz
Just Google "Silica Gel Packets" and you will find several companies selling these products.