http://www.unmuseum.org/cryskull.htm

http://www.world-mysteries.com/sar_6_1.htm

Researchers found that the skull had been carved against the natural axis of the crystal. Modern crystal sculptors always take into account the axis, or orientation of the crystal’s molecular symmetry, because if they carve “against the grain,” the piece is bound to shatter — even with the use of lasers and other high-tech cutting methods.

To compound the strangeness, HP could find no microscopic scratches on the crystal which would indicate it had been carved with metal instruments. Dorland’s best hypothesis for the skull’s construction is that it was roughly hewn out with diamonds, and then the detail work was meticulously done with a gentle solution of silicon sand and water. The exhausting job — assuming it could possibly be done in this way — would have required man-hours adding up to 300 years to complete.

Under these circumstances, experts believe that successfully crafting a shape as complex as the Mitchell-Hedges skull is impossible; as one HP researcher is said to have remarked, “The damned thing simply shouldn’t be.”

another mystery!

sadly, the British museum hold this skull, but keep it in storage 😐