  Visible afterglow counterparts have now been detected for two GRBs (970228
and 970508) but are absent, with $L_{opt}/L_{\gamma}$ ratios at least two
orders of magnitude lower, for other GRBs, e.g., 970828. The causes of this
variation are unknown. Any correspondence which could be discovered between the
gamma-ray properties of a GRB and its $L_{opt}/L_{\gamma}$ would be useful,
both in determining the GRB mechanisms, and in allocating resources for
counterpart searches and studies. This paper presents the gamma-ray spectra of
GRB 970228 as measured by the Transient Gamma-Ray Spectrometer and comments on
characteristics of this GRB compared to others that do and do not have
observable counterparts.
