Stone is a natural material and has no pollution. When I was a child, some household items at home were made of stone, such as garlic paste, and some of the earliest utensils were also made of stone.

However, it does not rule out unexpected situations. After polishing and soaking in some drugs, they may consider beauty and so on when making, and may ignore whether it is harmful to human body.

But if some brands or families do it themselves, it will be very safe.

I still suggest the best glass for drinking cups.

I hope my answer can help you!