Without the information I requested I can only give you a general answer, but I hope this helps. You can still upload photos even if the question is marked as completed. From what I understand 975 is 97.5% pure silver and is pretty rare. It is usually marked on only the finest silver jewelry. For a valuation please upload photos.
I hope this information was helpful!
I am happy to answer follow-up questions.
If you want to sell your item then here are a few suggestions:
Facebook Marketplace, NextDoor.com, Webstore.com, Varagesale.com
GoAntiques.com, Truegether.com, Mercari.com, Wanelo.com, Poshmark.com, Bonanza.com, Etsy.com, eBay, Pamono.com, and Chairish.com.
If you have several jewelry items then start a new thread/request per item. If you write
'FOR ANNA' in headline the question comes to me.
I strive to always provide five-star service, please let me know if you like more information about your item. As the assessment is made online and with the reservations and uncertainty it provides, I would recommend a physical assessment before a possible sale.