The word luz in Hebrew (Hebrew: 'לוז') means nut or almond. Because of this it became associated with the small bone at the top of the spinal column (the first cervical vertebra, C1 or the Atlas), underneath the brain, on the top of the spine, (the bone where the knot of the tefillin rests). It is about the size of a kernel of barley. The Zohar states that the luz is the bone in the spine that appears like the head of a snake, implying that is the sacrum, because the sacrum is the only bone in the spine that looks like the head of a snake. The sacrum has similar significance to the luz as a source of resurrection in Egyptian and Greek cultures contemporary to the Zohar and Talmud. The sacrum has a pattern of dimples and shape that appear similar to those of the almond shell.