Thrifted pendant - what did I get?

[triscodiscuit]

Hello! Snagged this pendant for a song - the bail is 18k, and the pearl is 10.4mm around. What sort of pearl is this most likely to be?

 

[jshepherd]

This looks like a freshwater pearl.

 

[ennui]

Snagged this pendant for a song - the bail is 18k

If it came with an 18K chain, too, I'd like to sing that song.