This may seem obvious, but it is absolutely crucial that you wear shoes while working with glass. Not sandals, not slippers, not open-toed fashion statements, and certainly not unprotected bare feet, but real, honest-to-goodness sturdy shoes which enclose your entire foot. You might even consider steel-toed boots.
I speak from experience, my friends. One day, while trying to salvage glass from a stepping stone damaged by a clumsy customer, a hairline crack grew into something much bigger. Half of an 18” concrete stepping stone fell off my work table and onto my sandaled foot. Not pretty. It took a full year and then some for my toenail to reach its previously healthy and attractive state. Naturally, I was working alone, but I managed to crawl to my bed and elevate my foot on the headboard without passing out. But it was close.
I made two mistakes. The first was not wearing a real shoe. The second was trying to salvage this stone. Take it from one who’s been there. If your stone is dropped and/or cracks for some reason, don’t try to save any of it. Take it straight to the dumpster and move on.
My point is simply this. Use common sense, be extra careful, and have a healthy respect for the damage that concrete and sharp glass can do to the human body. Keep young ones at a safe distance and insist that they also wear shoes if they are watching or helping. Tiny little pieces of glass that you may not see might end up embedded in the bottom of a foot. A nice crunch is a better sound than screams of agony. Stitches are no picnic for the injured party or the family member or friend who is there to watch the doctors work.
So, be safe and keep focused on the work before you, and you will hopefully avoid serious injury.
