If you must stay with glass shelving you could replace it with safety glass, as in windshield glass. It's a laminate which should help dampening. Acrylic would be an even better replacement...
Best isolation device
I am currently running a tube pre and solid state amp. I am trying to decide on a set of feet to set them on. The problem is that I have a glass and steel belo rack. Wife. I am not sure I will have enough clearance for a platform as well the cones. I have considered black diamond and mapleshade. I just want something that will work on glass. Thanks for the help.