The reverse pic is upside down; the "Q" is in the exergue, at the bottom of the coin.
Turned right way up:

I can make out a "Britannia-like" seated figure on the right, what appears to be a standing figure on the left, and a small angel-like figure of Victory between them. Can't make out much of the legend.
A check on Wildwinds for coins of Aurelian with these attributes and "Q in ex" came up with
this coin, which looks a pretty good match:

The legend should read ROMAE AETERNAE, or perhaps just ROMAE AETER. References are Sear(1981) #3168, Sear(1988) #3268, RIC #142F, Cohen #222. There's actually an error there in Wildwinds; the description given is for a coin where the standing emperor and seated Roma have swapped places (Cohen #219). I only have Sear (1981), in which the value for #3168 is quoted as £16 for typical condition specimens, which is slightly above average for an antoninianus of Aurelian.
A total of five of these coins are recorded in the Wildwinds sales database; prices realised for these coins range from 99¢ to $26.60.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis