You are looking at a Aquamarine skull. The skull is 0.6 inches from front to back.

Aquamarine resonates to the energy of the ocean, helping the holder to connect with the nature spirits of the sea. Seamen carried Aquamarine in ancient times to promote safe travel on the water and to protect against drowning. The soothing energy of Aquamarine makes it perfect companion to use as a stone of courage, protection, and to calm fears and phobias. Aquamarine is used most often with the Throat Chakra to enhance spiritual communication and to clear communication blocks. Aquamarine helps to promote verbal self-expression. Work with Aquamarine to help overcome judgment of others and encourage tolerance. Physically, Aquamarine is excellent for ameliorating ailments of the Throat Chakra organs such as the thyroid and the pituitary, and can calm sore throats. Aquamarine is also helpful for allergic responses, by its action of calming an over reactive immune system.