This is a very finely made ring! In fact, we are very surprised that we couldn't find any designer hallmarks. The quality is of Harry Winston, Hammerman Bros, or Oscar Heyman.
The center stone has been removed and replaced to get the exact weight of 4.91ct. The bombay style ring has the center ruby surrounded by a row of fine quality round brilliant diamonds weighing approx. 1.50tcw and outside of the diamonds are approx. 2tcw of rubies.
This was sent to GIA# 6204539439 which concluded the center as a natural untreated and UNHEATED Red Ruby from the famous mine in Burma. The most expensive rubies on the market today are unheated rubies from Burma making this a very special ring!