One of the most important aspects of the Constellation-X x-ray optics development is the fabrication of lightweight mirror segments. Given its multi-faceted requirements, i.e., good angular resolution, light weight, and low production cost, we have adopted a glass slumping or forming technique that takes advantage of the naturally excellent microroughness of thin float glass sheets. In this paper we present measured quantities of formed mirror segments and compare them with requirements to show that the formed mirror segments have met all except the sag requirement. The larger than acceptable sag error may be an artifact of the measurement process. It may also be caused by coating stress or residual thermal stress resulting from the slumping process. Our immediate future task is to identify the source(s) of the sag error and address them accordingly.