  A macroscopic single crystal of $\gamma_{\rm II}$-Li\(_2\)FeSiO\(_4\) has
been grown by means of the high-pressure optical floating-zone technique.
Static magnetic susceptibility $\chi$ implies that the
tetrahedrally-coordinated Fe$^{2+}$ ions are in the high-spin, $S=2$, state.
While a sharp decrease in $\chi$ implies long-range antiferromagnetic order
below \tn\ = 17.0(5)~K, the presence of a broad maximum at $T_{\rm m} = 28$~K
suggests quasi-low-dimensional magnetism. Applying magnetic fields along the
easy magnetic $a$-axis yields additional contributions to the susceptibility
$\partial M/\partial B$ and magnetostriction for $B > 7$~T, and an anomaly at
$B\approx 14.8$~T.
