"The topaz 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 into the spirit world. It strengthens and clears the mind."
Along with the other gems of the land, the Topaz was created when, as foretold by the fortune-telling stones of the Torans, fire and water "attacked" the Land of Dragons. The Topaz was found in the earth of Topaz territory and became the talisman of the Del tribe. It was kept in a glass case in Del's meeting hall. 
Tales of Deltora
After acquiring the Diamond, Emerald and Lapis Lazuli, Adin set out to collect the Topaz forth, despite beginning his journey in Del. He returned to claim the gem after obtaining the Lapis Lazuli, dressed in Mere clothing and wielding a bow and arrows, which made the guards of Del's gates mistake him for a lord from overseas. Adin introduced himself as the Archer of Azzure and demanded that the citizens of Del be summoned so that he may speak with them. Once everyone was gathered, he told them of the Belt he was constructing and asked that they follow the example of the Jalis, Dread Gnomes, and Mere and grant him the Topaz. The members of the city council, entranced with the rest of Del by the supposed stranger's majesty, began debating who would have the honour of bestowing the gem to him, but Violet recognised him. She was confused as to why the people were calling him by a different name and asked him why he left. The crowd was enraged at having been tricked, but Adin managed to hold them back for a moment. Master Gabb, one of Del's council members, lashed out at him verbally, belittling him as a "dirty-faced blacksmith". Adin pointed out that his reaction was the reason that he came as a stranger, and again asked them to consider his request. He earned the people's support, and added the Topaz to the Belt.
The Topaz later assisted Adin in obtaining the Opal. During a full moon, the gem's connection to the spiritual plane allowed the spirits of his ancestors, Liza, Dodd, and later Opal the Dreamer, to appear and help him.
The Forests of Silence
After being stolen by the Shadow Lord, 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 did not seem to like leave his hollow, the Topaz presumably landed near the centre of Mid Wood. The Topaz was instrumental in recruiting Jasmine as, after Gorl was defeated, a vision of her mother, Anna, appeared and convinced her to join Lief and Barda. As the first gem the trio found on their quest, Lief fitted the gem into the Belt's first medallion.
The Lake of Tears
Lief placed his hand on the Topaz, hoping it would help answer the giant's question. Inside Nij and Jod's house Lief sat down with his hands on the stone. While Jasmine and Barda were under their spell, he remembered that the Topaz strengthened and cleared one's mind and realised that it was by its power that he could resist the spell. He grabbed Jasmine and Barda's hands and placed them on the Topaz, and they, too, could resist it. During their escape, Barda suggested Lief use the Topaz to figure out how to cross Nij and Doj's moat.
The Topaz helped calm Lief while thinking about Thaegan and relaxed him as he went to sleep.
At the Lake of Tears, Lief, remembering that the Topaz was strongest during a full moon, placed his hand on the Topaz, clearing his mind and giving him hope. After retrieving the Ruby, Lief placed it in the medallion next to the Topaz.
The Topaz has several powers relating to the mind and spirits. It "protects its wearers from terrors of the night", presumably meaning that it calms them, and it sharpens and clears the user's mind. The latter has been displayed by Lief numerous times, wherein he used the Topaz to assist in solving riddles and puzzles. It also "opens doors to the spirit world", which allows people close or related to the wearer of the Topaz to manifest themselves. When strengthening the mind, the Topaz enables the wearer to see through pretense and evil magic.
The Topaz is at its strongest during the full moon, a fact Lief used to his advantage when he attempted to destroy the Shadow Lord's crystal. When all the people of Del were concentrating their thoughts on Lief during a full moon, Lief was able to hear their thoughts and used them to spur him on. The Topaz can also strengthen Topaz dragons and wake them from their enchanted sleep.
- The Topaz was used the most out of all other gemstones.
- The Topaz was the symbol of Adin's home tribe, and was the fourth jewel to be placed on the Belt by Adin, and the first to be fitted by Lief.
- The Topaz was at first considered by Adin to be put in first, but it was decided against. The Topaz was later guarded by a Jalis, who were the first to give their talisman to Adin, and was the first to be recovered.
- The Topaz was the jewel that was away from the Belt the shortest.
- The Topaz's tribe Del, and the Amethyst's tribe Tora together make the word "Deltora." The T in Topaz is in the exact middle of the word.
- Rodda, Emily. Secrets of Deltora. Scholastic Australia. 2008.
- Rodda, Emily. Tales of Deltora. Scholastic Australia. 2005.
- Rodda, Emily. The Forests of Silence. Scholastic Australia. 2000.
- Rodda, Emily. The Lake of Tears. Scholastic Australia. 2001.
- Rodda, Emily. Dragon's Nest. Scholastic Australia. 2004.