Hi Hansel, the one pictured with the CA's is just over 11/16" and glows when looking through it, also it has no eye.
As I mentioned, I always based them on their immediate color, the CA's seem to have a blue tint when viewed in hand and have a more transparent base with swirls visible, the Akro moonies I have all glow and the white flinties do not glow, to me a white flintie has the typical eye and does not glow, not many of my glowing moonies have the eye,I am not sure when I made this determination on categorizing them, it must have been long ago but to me the Akro moonies and flinties all seem to be more "white" in hand with less transparency.
Interesting question now that it has been asked, a moonie glows and white flintie doesn't??
Many years ago at the shows I would spend quite a bit of time with Stanley Block and Bob asking questions and sharing thoughts about particular marble characteristics, maybe it was Stanley who gave me the CA blue tint clue and the Akro moonie and flintie differences??.