Finally got to sit down and go through some of the non-Kyzikos fractions from my Kairos lot. This is one of the smallest and lightest coins I have ever handled.
Troas, Dardanos
5th century BC
AR
Hemitetartemorion 5mm, 0.07g!
Forepart of horse galloping left
Rooster running left
Unpublished; possibly unique?

I was able to find one instance of a tetartemorion of the same design:
https://www.numisbids.com/n.php?p=l...1171&lot=220Until the introduction of bronze coinage, the Hemitetartemorion was the smallest value coin in use in the Greek world (the electrum 1/192 stater was slightly smaller, but valued more). Worth just 1/8 obol or 1/48 drachm, the safest way to take them to the market was under one's tongue.