Conclusions from small denominations with same obv. / rev. :
Modules H and J have an identical obverse (Alexander head) and an identical reverse; however, they span module I that has a different obverse (Ammon head). The coalescence of adjacent modules with the same obverse and reverse that led Le Rider and de Callataÿ to make two pairs of small coins (i.e., Ptolemy II’s modules E, F and G, H) into two, rather than four, denominations is not possible with modules H and J of Ptolemy III. This is because module I (See module I ), with a modular weight intermediate between the adjacent H and J, has an Ammon obverse that differs from the Alexander obverse of both H and J.
If the Ammon head and the Alexander head indicated different denominations, the coalescence of the identical Alexander head modules H (17mm, 3-5g) and J (13mm, 1-2g) presents a confusing weight/size range for denomination I (16mm, 2-3g) that lies within the wide weight range for a H=J (13-17mm, 1-5g) coalesced denomination. Just as the identical obverse and reverse on modules A, C, D, Fi and I does not indicate the same denomination, the identical obverse and reverse on H and J also does not indicate the same denomination.
Since the Ammon head (on I) and the Alexander head (on H and J) do not indicate different denominations perhaps modules H and I, with little or no difference in size and a relatively narrow weight range (16-17mm, 2-5g), are the same denomination. They would be like module F that exists as the two types Fi and Fii (25mm, weights 8-13g) with different Ammon and Alexander heads.
Since we can now accurately and rapidly measure weights, we can be more aware of small weight differences than the ancient Egyptians. Yet, coins with small weight differences were produced and were no doubt useful in the market. Whether they were identified by weight or size, the Ptolemaic mint did not put denomination marks even on the smallest of Ptolemy III's coins.
It should be noted that coins H, I and J are part of a denominational set (together with A, C, D, F, and G See table) of Ptolemy III that is unified by each coin showing the same control mark. These coins were produced near the same time and very probably under the same unified policy. With the exception of module G (that differs only by having a cornucopia at the eagle's shoulder) none of the coins in this series has a unique obverse or reverse that would indicate its denomination.