Celtic Triquetra Knot Protection Amulet Purple Quartz Gemstone Heart Pendant Necklace Best Amulets Collection. Celtic Triquetra Knot Protection Amulet Purple Quartz Gemstone Heart Pendant NecklaceCeltic Triquetra Knot Protection Amulet Purple Quartz Gemstone Heart Pendant Necklace Pendant Size: 45mm (about 2 inches) Comes in Purple Quartz Gemstone and Base Celtic Charm Comes with Adjustable Necklace, Shortest: 15 inches, Longest: 24 inches Comes with Branded Packaging