Rosebower trademark?

Hi all,

I am just doing some research on my Grandmothers ring. She had some rings passed down to her and we are trying to find more information on this unique pretty thing. I’m guessing it’s Opal and Pearl seeds but not sure if Gold or anything else but does have a trademark on the inside. I don’t know much on jewelry so help is appreciated

 

Gorgeous ring, and yes, Rosebower by M.B. Bryant & Co, New York, early 20th century.
http://jarrett.fabpage.com/jewelrytm4.htm

I think the mark is earlier than the M.B. Bryant & Co mark of the three rings in a cartouche in this 1922 catalogue page:
http://chicagosilver.com/jmarks3.htm