Topaz

"The Topaz, symbol of faithfulness, is a powerful gem, and its strength increases as the moon grows full. The Topaz protects its wearer from the terrors of the night. It has the power to open doors to the into the spirit world. It stengthens and clears the mind, enabling the wearer to see through pretence and evil magic." - taken from the Belt of Deltora

The talisman of the Del tribe and the fourth gem Adin acquired, the great Topaz holds the center medallion on the Belt of Deltora. The Topaz on the Belt of Deltora has demonstrated some telepathic abilities; albeit it was on a full moon and Lief had instructed almost the whole of Del to think of him. It also strengthens Topaz dragons. The Topaz was dropped somewhere in the Forests of Silence, where Gorl found it and set it into the hilt of his sword. As Gorl doesn't seem to like leave his hollow, the Topaz preseumably landed near the center of Mid Wood. The Topaz was instumental in recruiting Jasmine as, after Gorl was defeated, a vision of her mother, Anna, appeared and convinced her to join Lief and Barda. It was the first gem the trio found on their quest.