Trefoil Knot Pendant by St Justin of Penzance Pewter Pendant £15.00 New stock arriving soon. Trefoil Knot brooch The Celts used knotwork to decorate many of their artifacts. To them, the intricate patterns woven into spirals and knots symbolise the continuity of life. Width: 27mm Height: 30mm 18″ tin-plated curb chain. Supplied in a satin and velvet-lined gift box. The venerable alloy of pewter is made of 92% tin, with copper and antimony to harden it and enhance casting. All of our St Justin Pewter products are LEAD FREE.