lab+8

How would ancient cultures have manufacture stone tools?: porque antes asi, todas las culturas eran de piedras, como los hombres cacavernicolas creaban sus armas y asi poco a poco se fue creando la cultura

What other minerals would they have used to cut and form them?, la piedra, el acero, la madera

How important would these tools have been to their civilization? me parece de suma importancia porque hace que tengamos mas cultura, mas cosas a saber de nuestra historia, mas tecnologia a la vez ya que con esos materiales se pueden hacer cosas asombrosas.

Write your answers in your wiki and then come back to them after reading what others have to say in this travel China guide: La utilizacion de armas en nuestros dias comienza en la edad de piedra, los cavernicolas, utilizaban la piedras pàra crear armas para la caza y la defensa. ahora en nuestros dia gracias a la tecnologia la utilizacion de estas piedaras han avanzado mucho, como popr ejemplo: el basalto y la arenisca se utilizaron para herramientas para afilar, Firestone chert son utiilizados como armas o herramientas y huesos, maderas, astas y los depositos se utilizan muchos, gracias a la piedra toda esta herramientas ha servido para nuestra civilizacion

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Ancient Chinese people may have used diamonds to polish their stone axes to mirrorlike finishes, according to a new analysis. Other than pushing back by several thousand years the date for the first known use of diamonds, the findings also suggest that Neolithic Chinese societies were more technologically advanced than previous studies had shown.  2.

Some sections of the ax surfaces are almost as smooth as some silicon wafers used to make computer chips, says Peter Lu, a physicist at Harvard University. "Somehow, Stone Age people . . . were able to make something smooth enough that you could pattern a circuit on it," he says. In an attempt to discover how the polishing was done, Lu obtained four ceremonial burial axes from the tombs of two Neolithic Chinese societies—the Liangzhu culture and the Sanxingcun culture—that once inhabited parts of southern China near what is now Shanghai. The stone axes had been dated by others to between 4000 and 2500 B.C. 6.

"Lu and his colleagues are the first to seriously address the question of what abrasives were used [in Neolithic China]," says Janet Douglas, a conservation scientist at the Smithsonian Institution in Washington, D.C. The new work also indicates that ancient Chinese artisans could have used diamond to work jade into thousands of smooth, gleaming objects, she says. 7.

To test his theory, Lu conducted a series of polishing experiments on one of the burial axes. Using a diamond saw, he sliced the ax parallel to the polished surface and then buffed the new surfaces with commercial polishing equipment using three abrasives: diamond, corundum, and quartz. 9.

To determine what kind of stone the axes were made of, Lu used X-ray diffraction, scanning electron microscopy, and electron microprobe analysis. These techniques enabled him to determine the axes' chemical composition as well as the crystal structure of the stones' minerals. He found that all four axes were composed primarily of three minerals, the most abundant one being the aluminum oxide called corundum, which is the stuff of rubies and sapphires. Corundum's presence was a surprise, says Lu. 8.

There are two known diamond deposits within 300 kilometers of the burial sites, a distance that could have been traversed by Neolithic people, Lu notes. 3.

It's the second-hardest mineral on Earth; only diamond is harder. Lu reasoned therefore that the only mineral strong enough to polish a corundum-rich ax would have been diamond. "Everyone thought the ancient Chinese were using quartz" for their polishing, he says. Quartz, however, is too soft to buff corundum into a shine.

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Lu also wonders whether Neolithic societies polished jade with diamond, since it would have been a more efficient abrasive than quartz.


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