The uniqueness of blue quartz is due to properties that are uncharacteristic in ordinary quartz, opalescence, chatoyancy, and asterism. In addition, all blue quartz specimens are highly fractured and contain inclusions of rutile or other minerals.Blue quartz has an opalescent or "waxy" (according to them) luster, which is changeable ("chatoyant") depending on the light. Asterism is defined as the "illusion of a star-like figure" in a mineral, and seems to show up in photomicrographs of blue quartz.
There are several things that can cause quartz to look blue. The first is the presence of inclusions that scatter visible light in the blue part of the spectrum - usually zoisite, tourmaline and rutile. The blue color may also come from closely spaced, subparallel microfractures, which are found in all blue quartz samples. Finally, it has been suggested that the presence of titanium (in the form of rutile or ilmenite) could cause the blue color, although there are specimens of blue quartz with no titanium, and quartz of different colors that contains large amounts of titanium.
Here's the photo from a 2002 Virginia Minerals (from the rock garden in front of their building in Charlottesville):