I'm reading a rather obscure book on Epicurus by a Russian guy called Jan Powarkow. Unfortunately, to my knowledge, there's no English translation of it. I came across this footnote and I was absolutely amazed by it. I didn't realise Greek Atomism was so advanced. I heard about 'atomos' but when I read about 'ameres' I told to myself: no way Greeks came up with this!
Anyway, I thought this fragment is interesting enough so I leave English translation for you:
[...] A. F. Losiew writes that traditionalists in the history of philosophy do not attribute any significance to the fact that Greek Atomism fundamentally distinguishes the terms atomos (indivisible) and ameres (not consisting of parts). S. J. Lurie quotes a number of fragments to document this distinction, but it should be emphasized that the most important of them were previously quoted by H. Diels.
In a nutshell: atomos differ from ameres in that despite their indivisibility, they consist of certain parts, while ameres no longer consist of any parts and they themselves constitute the boundary of division, being both indivisible lines, indivisible planes, and indivisible bodies and generally indivisible units. Of course, ameres constitute a kind of intellectual construction, almost immaterial. In any case, they have no weight and are conceived as if within the atoms themselves. [...]