Identifying Gold Rope Necklace Mark: Binder Bros. Inc.?

Question

Gold rope necklace   I can read the following on the necklace clasp:

1)  20 | 2 K G F

2)  There are two overlapped circles, each with a B in it.

In reading on-line, I understand the '20' part of the equation but not the '2.'

The necklace measures 15".  

Thanks for any feedback!!!

Answer
Hello Elizabeth and thank you for your inquiry. Your necklace mark is probably for Binder Bros, Inc., a jewelry company in New York City active in 1935. The mark you have is probably 1/20th 12K GF .  Below is a site that give a more in depth description of jewelry markings.  Just click on or copy and paste it into your browser address field and hit enter:

http://chemistry.about.com/od/jewelrychemistry/a/metalmarks.htm

Hope this helps and enjoy your necklace !

Sally at
jarrettsjade.com