This unusual example of "antenna Quartz," occurred as a brief layer in  a Quartz vein in the Goboboseb mountains in Namibia. The vein was frosty white quartz, and then they hit a layer where there were secondary growth of Amethyst on the white quartz crystals. Some of the secondary growth may be considered "reverse sceptering," as the Quartz grows skinnier and more narrow, compared with the opposite being "scepters," where they expand outward. 

This piece was the best from a lot I purchased of the Charlie Key collection. What makes this the best example is its broad array of crystallization on a single piece. There are clear quartz crystals that turn purple but have no obvious shift in structure, then there are ones that scepter as they turn purple, and others that become narrower as they turn purple. No damage.