  In this work, the {\it ab initio} calculations have been carried out to study
the oscillator strengths corresponding to `forbidden transitions' of
astrophysically important electromagnetic transitions of singly ionized zinc,
Zn II. Many important electron correlations are considered to all-orders using
the relativistic coupled-cluster theory. Calculated ionization potentials are
compared with the experimental values, wherever available. To our knowledge,
oscillator strengths of magnetic dipole and electric quardupole transitions are
estimated for the first time. The transitions span in the range of ultraviolet,
visible, and near infrared regions and are important for astrophysical
observations.
