The scarab was based on the image of the dung beetle, or Scarabeus Sacer, and it was used by the ancient Egyptians for many purposes such as recording historical events or inscribing prayers to be placed on mummies for protection against evil. Scarabs were made from a wide variety of materials such as carnelian, lapis lazuli, basalt, limestone, schist, turquoise, ivory, resin, steatite, and bronze. Most scarabs were made of steatite which was then covered with a turquoise coloured glaze. The stone was soft and easy to work, but when glazed, it became hard and durable. It was often carried as an amulet cast from gold or carved from semiprecious stones. The flat underside has a design carved into it that could be used as a signet.