Topaz is the only one of the three gemstones - jade, topaz and peridot - that is not considered a traditional birthstone. Jade is the birthstone for the month of March, while peridot is associated with August.
Topaz is however often linked to November, and citrine is sometimes considered a birthstone for that month.
Birthstones can vary depending on culture and tradition, and changes to the list are not uncommon.