Small Diamond Trefoil Locket NecklaceDevon Woodhill small diamond trefoil locket necklace. "Let the light in". The trefoil symbol allows light to pour into the wearer, creating a window into the self that is both grounding and uplifting. In Gothic architecture, the trefoil was used as tracery, which is ornamentation around a window or door. Used often in churches of the period, it allowed the light to pour into the nave. Diamonds (0. 18ctw) 18mm, 16" 1. 3mm cable chain 18k Gold locket,