My quartz melted in the microwave and it's making fumes, what does this mean?

I, 25 M, bought high quality quartz from my sister for a pretty good price. They look normal and don't have anything on them. I wanted to know how to take care of them so they don't chip or anything, and a lady online said something about charging them? I don't know the purpose of this, but she reassured me that quartz is supposed be charged apparently. I asked my sister and she said to microwave it. When I put it in the microwave, it began melting and now my house is full of fumes. I got dizzy and started coughing. I've aired the place out but what the fuck happened? Isn't quartz supposed to be strong and not melt?