  We explore the scenario where the core of a neutron star (having experienced
a transition to an up and down quark phase) shrinks into the equilibrated quark
object after reaching strange quark matter saturation density (where a
composition of up, down and strange quarks is the favored state of matter). The
overlaying (envelope) material free-falls following the core contraction
releasing upto 10^{53} {\rm ergs} in energy as radiation, partly as a result of
the conversion of envelope material to quarks. This phenomena, we named
Quark-Nova, leads to a wide variety of ejectae ranging form the Newtonian,
"dirty" to the ultra-relativistic fireball. The mass range of the corresponding
compact remnant (the quark star) ranges from less than 0.3M_{\odot} up to a
solar mass. We discuss the connection between Quark-Novae and Gamma ray bursts
and suggest the recently studied GRB011211 event as a plausible Quark-Nova
candidate.
