Can the ring you bought be adjusted?
 
Adjusting a ring more than two sizes in either direction can noticeably impact its look and structure, and is often not recommended by jewellers.
 
Ring Resizing
General
Vintage and antique rings contain hallmarks that add to the value of the ring. When resizing a ring, be sure to discuss the position of the cut with the jeweller. Under no circumstances should the cut damage the hallmarks since this would significantly reduce the value of the ring.
 
Gold and Silver Rings
Increasing the size of a gold or silver ring typically requires gently hammering the ring around a sizing shaft. This will cause the shank of the ring to thin slightly and, in some rings; the end result will not be perfectly round.
 
Platinum Rings
Platinum is a more difficult metal to resize because of its density and strength. Some jewellers will not resize platinum.
 
Gemstone Rings
Care must be taken when resizing rings containing gemstones since resizing can affect the setting, causing the gemstone to become loose and eventually lost. Usually an incision is made in the ring to remove or insert extra metal. This is also the preferred method for increasing rings by more than one full size. The adjustment may leave a visible seam or an invisible weak point, but a professional jeweller can position flaws out of sight.