Board Thread:Speculation House/@comment-28189972-20160414231859/@comment-4010415-20160414235511

When fighting Amber, she kicked up dirt and melted it with the Dust in her dress to make glass. The obsidian comes from her using Dust to spawn lava and then rapidly cool the lava into obsidian.

It seems like Huntsmen/Huntresses in general can manipulate whatever comes out of the Dust they're using, considering that Weiss frequently chooses the shapes that the ice spawned from her ice Dust take (Curved wall, flat sheet, dome, giant sword). Neon chose for her ice to encase Yang's arm and leg the way that it did, while her ice Dust created spiky ice crystals when she attacked a Paladin's leg. It seemed like Dew could control the movement of the tornadoes she created.

Things like that.