Watch List notes:

The Eparch Collection of Roman, Byzantine and Islamic Weights
BYZANTINE COIN WEIGHTS

Circa 5th-7th century. Weight of 5-nomismata (Brass inlaid with silver, 19x19x4mm, 20.95 g), a thick, square coin-weight with plain edges (as MAH B1), nomisma of 4.19 g. Six-pointed star above Ν Ε, all inlaid in silver. Rev. Plain. Cf. MAH 192 (a 6-nomismata weight with a star), and Kürkman 50 (a 1-ounkion square weight with supposedly a Christogram at its center, though this seems a misreading). A clear piece, and most unusual with the star in place of a cross. Rather rough surfaces with a dark, golden-brown toning. Very fine.

From the Eparch Collection.
The star above the weight letters on this piece is apparently quite uncommon: normally there is either a Latin or a Greek cross. This star could be a version of the Constantinian chi-rho monogram, but it might also be a more neutral, non-religious symbol.