Ring repair - recommendations please

Hi, I’m hoping someone may be able to help me. I was gifted a sterling silver ring with three garnet gemstones for my 17th birthday, off my mum. She’s since passed away and the ring is extremely sentimental to me.

Earlier today I noticed the middle gem is missing. After retracing my steps I’ve been unable to find the gem so I was wondering - are there any jewellery shops in Manchester or Salford who could source a gem similar looking to the other stones (I don’t think they’re precious of any kind) and re-fit it into the ring?

I’m really hoping it can be fixed and looking for recommendations for shops which are reliable and specialise in these kind of repairs. I don’t mind paying up to £100 if it ends up looking the same.

TIA.

TLDR: Any jewellery shops in Manchester/Salford who specialise in replacing missing gems?