I only have my diamond channel set eternity ring five months and baguette diamond has cracked and shattered. What should I do?

Take it back to the jeweler with your guarantee papers.

I have taken it back and they said it is consumer damage, but we are sure it was not hit. We have asked for the manufacturer report, we still have not received anything yet.

You are "stuck" waiting. If it comes back as consumer damage I'd be in Small Claims Court so fast the dealer's head would spin.

Still getting no where with the jewellers, they have still not provided written assessment of damage. Want as to pay for an independent assessment of ring.

What does your warranty say? Can you give me the exact wording?

Our jewellery is guaranteed, for one year, to be free of manufacturing or material faults and to be suitable for the purpose it was sold as required under the terms of the relevant Sale of Goods Acts. You can return jewellery items to us for assessment and action if you have a claim under this guarantee. We may, at our discretion, repair, replace, or refund under the terms of the Sale of Goods Act.
Our guarantee does not apply to faults caused by accident, neglect or misuse of the goods.

So you are arguing defect and they are going to argue accident, neglect or misuse. Okay, that's a starting point.

This is what I would do - I'd take it to another jeweler but wouldn't give jeweler #2 the name of jeweler #1. I'd ask for a written opinion as to the cause(s) of the "damage/defect." It should be about the same cost as a new appraisal.

That opinon will determine what you should do next.