A «Crystallite Ingot» (クリスタライト・インゴット, Kurisutaraito Ingotto?) is an item in Sword Art Online that is used as a high-grade material in forging weapons. It is found in the X'rphan the White Wyrm's nest and the end result of the said dragon's diet of crystals - this crystal is its solid excrement.
The Crystallite Ingot is only found in the X'rphan the White Wyrm's nest in the West Mountain of the 55th Floor after starting a quest in the nearby village and was rumored to require the presence of a master smith in a party for the crystal to be harvested.
After Kirito's request of a new sword and breaking one of Lisbeth's masterpiece swords, Lisbeth informed Kirito of a dungeon on the 55th Floor where a dragon that eats crystals was rumored to drop a high-grade material. The two journeyed to the West Mountain dungeon and faced the crystal-producing Frost Dragon. Before Kirito was able to finish off the dragon, Lisbeth came out of her hiding place and the dragon used its blizzard attack upon sensing another player. Lisbeth fell into the dragon's nest, and Kirito went to break her fall. Kirito and Lisbeth, without a way out of the nest, spent the night there.
In the morning, while chatting over morning tea, Kirito suddenly stood up and ran towards the center of the nest where he dug up a Crystallite Ingot, as well as revealing that it was actually the dragon's solid excrement. At that point, the dragon returned to its nest, and Kirito and Lisbeth escaped from the nest by Kirito picking up Lisbeth and hitching a ride on the dragon by hanging onto its tail.
Back in Lindarth, Lisbeth took the Crystallite Ingot and prepared to forge it. After preparing herself in the event that she impressed Kirito with the new sword and thus she would confess to him, Lisbeth began to forge and smith the ingot into a sword. After a few hits, the ingot turned red and became the Dark Repulser.