Hanging 73 lb frameless glass panels on drywall
By far, the best approach is to attach either clips or a frame to studs (either wood or steel, depending on your construction).

If the panels are being arranged at the same level, you could run rails horizontally along the wall at the base and top of the panels. These could be made from two pieces of molding, one slightly thicker than the thickest glass panel (about 3/8 by 3/4) and another thinner wider piece on the face (about 1/4 by 1 to 1 1/4) creating a lip. These could be screwed into the studs and painted to match the wallboard.

In a concrete wall, the strip could be mounted using masonry anchors every 8 to 12 inches.



An alternative is to mount mirror clips at the top and base. 



However panels of this weight really need stud mounting, so the clips would have to align with the studs, and that might be a problem with spacing. In a concrete wall, mirror clips could be used, but again, need to be placed at least 4 per panel in the base.

It is theoretically possible to use mirror clips with other mounting devices, such as toggles, but you would need several in the base of each panel, as well as two at the top, and the weight would make this very iffy.