Abramelin, on 03 May 2012 - 01:02 PM, said:
As editing these days gives me a headache, I will post this in a new post:
Notable features at Pumapunku are I-shaped architectural cramps, which are composed of a unique copper-arsenic-nickel bronze alloy. These I-shaped cramps were also used on a section of canal found at the base of the Akapana pyramid at Tiwanaku. These cramps were used to hold the blocks comprising the walls and bottom of stone-lined canals that drain sunken courts. I-cramps of unknown composition were used to hold together the massive slabs that formed Pumapunku's four large platforms. In the south canal of the Pumapunku, the I-shaped cramps were cast in place. In sharp contrast, the cramps used at the Akapana canal were fashioned by the cold hammering of copper-arsenic-nickel bronze ingots.[8][10] The unique copper-arsenic-nickel bronze alloy is also found in metal artifacts within the region between Tiwanaku and San Pedro de Atacama during the late Middle Horizon around 600–900.
http://en.wikipedia.org/wiki/Pumapunku
Would tools - chissels - made from this alloy do the trick?
From the hardness yes, it would be somewhere around 5 (give or take 1 depending on the exact composition), that would be almost as hard as a modern pocket knife made out of knife steel, but at the same time much more maleable, that is the tool would have been more flexible and therefore less likely to break.
What gets ignored mostly, when we talk about bronze, is that it was used until after the Middle Ages for stone working. Iron was way to brittle at the time to make a satisfactory tool. It was not until steel became available cheaply that it was used by masons.
Edited by questionmark, 03 May 2012 - 01:11 PM.