No windows on Mars

In the fanciful drawings of a future Martian colony there are often glass domes or at least windows. What we know about Martian soil chemistry at this point is the glass as we know it could not be made there. There is ample silica but it's in a form that has never been used in glass making on Earth. The critical element missing is of course limestone which as it is biological in origin has absolutely no known source on Mars. Sodium carbonate is also virtually unknown from current data. Without those key ingredients glasses we know it cannot be made. This is far reaching effects not just from the fact that it will mandate that absolutely all agriculture take place under artificial illumination. It also means a rather dreary existence for those unfortunate to find themselves on Mars without a window.