Hi Cliff,
For
monograms on
Byzantine seals the
Numiswiki page is pretty much useless. The reason is that these
monograms on
seals are personal
monograms of the seal's owners, not imperial
monograms of emperor's names. There are hundreds of different
monograms published and thousands exist.
Your seal, however, has a
monogram that can be solved NIKOLAOV, the
genitive of Nicholas, who would have been the owner of the seal, assuming the letter at the bottom extremity is Alpha (and Lambda at the same time, of course).
The
portrait on the
obverse can well be Saint Nicholas as well, but from the photo I can't say for sure. For this time period (6th/7th century AD) St. Nicholas is quite
rare, but with the reading of the
monogram in mind, it would be a
good guess.
Regards
Gert