Bronze tessera from Heddernheim

Square bronze plate (Br. 0.024 D. 0.004). It used to be at the Frankfurt Museum but it seems to have got lost.MMM II 509 No. 253n and fig. 463.The front of the plate is polished and has been engraved with hardly readable letters. Wolff (in a letter to Cumont) explained it as a tessera but later on interpreted it as an exagium which does not belong to the Mithraeum.MMM II No. 441a.Soli i(nvicto).Underneath it an indistinct symbol, which looks like a G. Another reading, however, is (cfr. MMM I 365 No. 253n): Solidi G.