  The separation of quark and gluon initiated jets can be an important way to
improve the sensitivity in searches for new physics or in measurements of Higgs
boson properties. We present a simplified version of the shower deconstruction
approach as a novel observable for quark-gluon tagging. Assuming
topocluster-like objects as input, we compare our observable with energy
correlation functions and find a favorable performance for a large variety of
jet definitions. When applied to dark matter searches in mono-jet final states
limitations from small signal-to-background ratios can be overcome. We also
show that quark-gluon tagging is an alternative way of separating weak boson
from gluon-fusion production in the process p + p -> H + jet + jet + X
