Known as astragali. First century AD, the time of Christ. Actually made from the ankle bone of a sheep. Natural bone with the underside weighted with lead, it was used in games of chance. The irregular sides, 4 of 6 on which the die could land, generated different values based on the probability of the die landing on it. Numerous games using the knuckle bone die are known and its use is documented in ancient Greece and Greek mythology.