Thank you for contacting Mearto with your appraisal inquiry.

It is a beautiful and very special bracelet. Such antique jewellery are being offered at auction on a regular basis however you vere rarely see bracelets with a carat as high as 15 ct. The fact that the diamonds are set in platinum shows that it was an expensive piece of jewellery and that the diamonds used are of a certain quality. The use of platinum for jewellery of this particular sort was very popular in the early 1900s. And based on the style, materials and design of this bracelet I would date it to be from 1920-1930 in the Art Deco style.
It is a unique and very elegant and classic piece of jewellery that would most certainly attract the attention of both collectors and dealers if it came up for auction.
When appraising jewellery with a carat this high an expert would have to look at it in real life to determine the individual size of the diamonds and the colour/clarity of the stones. This is a piece of jewellery that could easily surprise in a positive direction if it came up for auction.

The estimate provided is for a well-advertised specialised jewellery auction, where I believe the bracelet has the best chance of realising its fullest potential. However, there is no measurement for the sentimental value you might attach to the lovely bracelet. Retail "asking prices" can be higher and vary.

Please let me know if you have any additional questions. I’m happy to help.
Thank you