RJ240 on gold

[Bonsai]

I bought some 18k gold earrings off therealreal . They're very beautiful. It was sold as no hallmarks but I found a small one inside the clip
rj240

I took them to a higher end pawn shop today to have them xray tested. they came back as 17k gold.

What does the hallmark mean and specifically the 240?

Thanks

 

[blingmeupscotty]

This may help?

 

[Bonsai]

This may help?

Thanks. I tried looking in to them but I didnt see much jewelry. I'll keep looking in to them and see what I find. Its possible the earrings are that old