Having so many birthstones for each month is confusing but sometimes convenient. I made a necklace for my mother, with the birthstones of her family members. One person insisted on having their stone be their favorite color, which was not the usual color of the birthstones, but one stone had that color as an alternative. (If we hadn't found that, I would have used the person's favorite color anyway, but this made it a bit easier to explain.)