All of the ancient stonecraft seen in Incan and Egyptian monuments and stoneware show smooth and slick surfaces, which means the rock was not processed in the manner that previously thought. A geologist  describes the nature of these ancient stone artifacts, Professor Ivan Watkins, assigned at the Department of Earth Sciences, at St. Cloud University in Minnesota, says that the primary indicator of how a stone was processed or 'worked' is the condition of the surface of the material at the microscopic level.  During his investigation, it was found that Incan and Egyptian stonemasonry had similar workmanship, indicating that the same technology was available across both nations at the time.

Because hard igneous rocks are extremely tough to cut, a mechanical and physical method of cutting them would leave uneven mineral surfaces because the rock would naturally crack along low angles if it was hammered.  Because stones like granite contain a mix of minerals with varying degrees of hardness, force applied to the stone's surface ( hammering, grinding, polishing with abrasives ) would cause the weaker planes to crack naturally and the tougher parts to keep together.

Consulting with geologist David Lindroth, at the US Bureau of Mines, Twin Cities Research Center, they both found that a focused laser, 100 watts of power, focused at an area 2mm in circular footprint can cut through any rock, and repeated passes using the same power can cut any stone down to size.  The light cutting through stone is called thermal disaggregation.

From the Archives: This live interview was recorded on December 7, 1996 on the nationally syndicated radio program, hosted by Laura Lee . See more at www.lauralee.com

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