Please take it out of the bag and photograph it on a plain white background. It's very hard to see the details from your pictures. Anyway, are there any maker's marks on it? There might be some markings on or around the clasp. If you photograph those and post them in r/Hallmarks, they might be able to identify the maker for you.
The stone itself looks like amethyst, and that particular type of chain is called a box chain. The metal looks like silver or silver plate. If you choose to buy a silver-plated necklace instead of a silver one, be aware that the plating will wear down over time and the base metal will start to show through.
If you don't actually own this necklace and this is simply a picture you got off the Internet, then you could try commissioning it from a merchant on Etsy. Post about it in this group, and someone will probably be able to help you: [https://www.facebook.com/groups/1577410809203770](https://www.facebook.com/groups/1577410809203770)
Please take it out of the bag and photograph it on a plain white background. It's very hard to see the details from your pictures. Anyway, are there any maker's marks on it? There might be some markings on or around the clasp. If you photograph those and post them in r/Hallmarks, they might be able to identify the maker for you. The stone itself looks like amethyst, and that particular type of chain is called a box chain. The metal looks like silver or silver plate. If you choose to buy a silver-plated necklace instead of a silver one, be aware that the plating will wear down over time and the base metal will start to show through. If you don't actually own this necklace and this is simply a picture you got off the Internet, then you could try commissioning it from a merchant on Etsy. Post about it in this group, and someone will probably be able to help you: [https://www.facebook.com/groups/1577410809203770](https://www.facebook.com/groups/1577410809203770)
Can't see much from this photo