Paltinum diamond earrings are a favourite of mine. I have a pair of 1950s platinum diamond earrings and love them. The white metal accentuates the whiteness of the diamonds. Robert the N letter will be the signature of the manufacturer and from Oslo to New York N letter manufacturers appear to abound. So you might ask Robert, if there are more than one N maker how can anyone determine?
There are lots of tell-tale clues to work out the N makers from each other. Is the letter N in a frame of some sort? A circle, diamond shape, etc? Or no frame? And the font style of letter, is also indicative. For exmaple, Ludwig Neresheimer & Sohne, Silversmiths, Hanau Germany 1893-1950s used a fancy stylized capital N. So if your N is not fancy, you can elliminate him.
