Striation evidence refutes copper bar grinding hypothesis. Striations on ancient Egyptian hard stone are typically deep, continuous, regular, and obvious - approximately 0.5 mm deep and 1-2 mm apart Experimental archaeologist Dennis Stocks achieved a grinding rate of approximately 2 mm per hour with copper tools and sand US Patent 7082939 for an improved frame saw cites a cutting rate of 30 mm per hour into granite

Experimental archaeology challenges the copper-and-sand grinding theory. Dennis Stocks achieved only 2mm/hr; Penn University tests produced microscopic scratches, not the deep ~0.5mm striations on ancient stonework. Dunn's copper-ground granite core came out smooth and polished, totally unlike the regular grooves documented on Egyptian artifacts.

Key Facts

  • Striations on ancient Egyptian hard stone are typically deep, continuous, regular, and obvious - approximately 0.5 mm deep and 1-2 mm apart
  • Experimental archaeologist Dennis Stocks achieved a grinding rate of approximately 2 mm per hour with copper tools and sand
  • US Patent 7082939 for an improved frame saw cites a cutting rate of 30 mm per hour into granite
  • Robert Moors Jr.'s 1991 paper proposed a 400 lb copper drag saw achieving 42 mm per minute cutting rate - 84 times faster than modern diamond blade saws, considered physically implausible
  • Grinding with a copper bar requires hacking an initial groove into the stone to get started, but Petrie documented thin slices of basalt sawn on both sides that would not require starting grooves
  • Chris Dunn ground out a granite core using copper and sand technique - the result was smooth and polished with only faint scratches, not the deep striations seen on ancient cores
  • Penn University experiments in the 1980s showed grinding produces only extremely fine scratches requiring a microscope to see, not the deep regular striations on ancient Egyptian stonework

Related site: Abu Rawash — view location, images, and history on the Ancient Nerds map.

Source: Evidence for Ancient Machining at Abu Rawash! by UnchartedX