The most famous portrait of Anne Boleyn in which she is wearing her signature necklace
If we are to judge from the few portraits of Anne Boleyn then her "B"- necklace must have been her favourite jewellery since it is featured in so many of them. Obviously, the "B" stands for Boleyn. After Anne had been executed the necklace (extraordinarily enough) passed on to her daughter, Elizabeth I, alongside another necklace of Anne's with the letters "AB" on it. During the Tudors it was common to wear jewellery with your initials on it, so Anne's necklace would not have been thought odd. As can be seen from the portrait the necklace consists of pearls with the golden "B"-pendant from which three large drop-pearls hangs.
It is difficult to see but the young Elizabeth is wearing a necklace with the letter "A" on it - almost certainly the one her mother left her