Help me identify this item.

[grandmothers_attic]

Please help me identify this item. I want to list it on eBay but don’t know it’s worth or how to describe it. All I do know, it’s a pin, blue  with a white circle on a gold/gold tone base, about 1/2” x 3/8”. Thank you in advance for any info you can supply. 

 

 

 

[melirena]

There's some kind of mark on it. What does it say? It may give you a clue.

[rockrancher]

I agree, we need to know what the back say....  could be helpful. thx