Evidence of silica ejection:

"Small kilometer-sized asteroids would also be hard to detect, however, and recent work by Orton et al. and Hammel et al. has strongly suggested the impactor was an asteroid, as it left only one impact site, did not reduce Jovian decametric radiation emission by contributing significant dust to the Jovian magnetosphere, and produced high altitude dusty debris full of silica, very different than what was produced by SL9."    http://en.wikipedia.org/wiki/2009_Jupiter_impact_event     Highlighting by Carper

"This key evidence is what forced scientists to say “this must be asteroid debris even though it can’t be…”, since comets do not have abundant silica. Of course, the ONLY other place that silica could have come from was…. yes, the rocky/ silica core of Jupiter. This is significant evidence that at least part of the core of Jupiter was liquidated and violently thrust upward to the surface."  JEC