Descent over the Glacier II.
Theoretically you may descend along the ascent, but this is rarely used.
Most people are crossing the glacier on the north of the mountain, called Ghiacciaio della Marmolada. There are two parts of the glacier; the top section is interrupted by a short ferrata in rock and than the main glacier leads to the Rif Fiacconi.
You may meet tourists without ice tools who try avoiding the top part of the glacier and go on the right hand site. This cannot be recommendable due to loads of free stones there. You can see them on the picture in the middle.
Normal way used also by mounting guides is across the glacier, on the right, but about 30 meters from the edge. The top glacier is just a snow field, there are no (or seldom) cracks. The problem for beginners on Marmolada is the gradient: nothing special in the beginning, but as the glacier goes down, the slope is steeper, so you cannot see the end.
Watch the picture with the blue climber who is on the normal way. There is another group on the right at the end of the snow field. This is the start of the short ferrata leading to the main glacier.