SkinWalker and others;
They are scientists.
Read the whole thing - please. On the Internet it's so many links like for some celebrity. But don't bother I will do a job for you people.
Copy from the net;
-Some of the skulls are believed to be between 5,000 and 36,000 years old.
-The skull is so strangely hypnotic that there is a story that the cleaning staff at the musem one time insisted that the object be covered with a black cloth before they worked around it at night.
-The Mitchell-Hedges skull is made of clear quartz crystal, and both cranium and mandible are believed to have come from the same solid block. It weighs 11.7 pounds and is about five inches high, five inches wide, and seven inches long. Except for slight anomalies in the temples and cheekbones, it is a virtually anatomically correct replica of a human skull. Because of its small size and other characteristics, it is thought more closely to resemble a female skull -- and this has led some to refer to the Mitchell-Hedges skull as a "she."
The Mitchell-Hedges family loaned the skull to Hewlett-Packard Laboratories for extensive study in 1970. Art restorer Frank Dorland oversaw the testing at the Santa Clara, California, computer equipment manufacturer, a leading facility for crystal research. The HP examinations yielded some startling results.
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."
Peace!
http://www.world-mysteries.com/sar_6_1.htm
http://com2.runboard.com/bcreativecosmosplanetaryforum.fconspiracy.t53
http://www.unmuseum.org/cryskull.htm