Approximately 1.75x0.75 inches.
Some uses for crystal skulls are to see visions of past, present or future; enhancing one's psychic abilities; healing and energy work; can be used as a tool to awaken human consciousness; believed to have magical powers as well as be transmitters and receivers of energy; self-awareness; creating balance and understanding the human creation and evolution.
Crystal skulls are most often associated with ancient Mesoamerican cultures, especially the Maya. If you have found a crystal skull that you feel drawn to that means your soul is searching for answers to the great mysteries of life, death, and rebirth. Many crystal skulls are designed and cut at specific angles representing a union of sacred geometry.