It depends on how the loss occurred. If the stone was lost due to a sudden, accidental event — for example, the ring was dropped or damaged and the stone dislodged — you may be covered under Accidental Damage, provided you have Full Contents Accidental Damage and the ring is correctly listed on your policy (if required).
However, if the stone simply falls out without any visible damage to the ring, the claim is likely to be declined. This type of loss is usually caused by wear and tear, poor maintenance (e.g. loose prongs), or faulty workmanship — all of which are excluded under the policy.
We recommend having valuable jewellery inspected regularly by a qualified jeweller to ensure settings remain secure. Review your policy booklet for more details.