The modern birthstone(s) for February are Amethyst. Traditional birthstone(s) are Amethyst, Pearl. Zultanite — gem-quality color-change diaspore from Türkiye — is not an official February birthstone.
Modern birthstone
The modern February birthstone list, established by the American National Association of Jewelers in 1912 and updated periodically since, includes: Amethyst.
Traditional birthstone
The traditional birthstone list (drawing from older European and Polish gem-month associations) for February includes: Amethyst, Pearl.
Where Zultanite fits
Not an official February birthstone. Amethyst (purple quartz) and Zultanite (color-change diaspore) share no mineralogy.
How birthstone lists work
There is no single global authority on birthstones — modern, traditional, mystical (Tibetan), and Ayurvedic lists all differ. Zultanite was discovered too late (commercial production began in the early 2000s) to enter any of the historical lists.