Linked Trinity Knot Necklace. The Trinity Knot is said to be symbolic the past, present and future in Celtic Lore, as well as representative of the Christian trinity. Here are three Trinity Knots, with the larger knot measuring 1 inch, and smaller knots 3/4 inch, across. All suspended on a 7 1/2 necklace. Pewter, made in Cornwall, England.