A wedding eternity ring with 50% coverage typically means that half of the ring's band is encrusted with diamonds. In this case, lab-grown diamonds are a sustainable and ethical option.

The ring could feature an alternating pattern of lab-grown diamonds set in a band made of both gold and platinum. The combination of gold and platinum provides both durability and a luxurious appearance. The gold can add warmth and traditional beauty, while platinum offers strength and durability.

Overall, this ring would be a stunning symbol of eternal love, with the lab-grown diamonds symbolizing your everlasting commitment and the mix of gold and platinum adding both style and strength to the design