If you're still young enough to remember your birthday, you probably also remember the special birthstone assigned to it. But at your age, we bet you don't really know the SIGNIFICANCE of your birthstone and what power the ancients felt would be bestowed about you by wearing it. December Birthstone: Turquoise Birthstone Properties: Alternative Birthstone: Lapis Lazuli Turquoise is the birthstone for December and the traditional gift to commemorate the 5th and 11th years of marriage. It's colo.