K. Rowling: "Wand Woods" at Harry Potter (website) (archived from Pottermore) ↑ Bloomsbury Webchat with JK ↑ Harry Potter: Hogwarts Mystery, Beyond Hogwarts, Volume 1, "AUROR CASE FILE: GRINDELWALD'S WAND" Achievement - Part 1, Side Quest "Your Auror Mission" ...
Rowling has also revealed that she discovered that Harry's wand wood corresponded to hisdate of birthin the Celtic tree calendar afterward, and decided to use the calendar to assign the wand woods ofRon WeasleyandHermione Grangeras a "hidden connection" between the three.[5] ...
[2][8] This type of wood contained powerful magic and was the rarest of all wand woods, but was said to be deeply unlucky and much more difficult than any other to master. Only a highly unusual person who was the superior of their company would find their perfect match with this wood...