Re: Pyramidiocy (was Re: Strange Maths)

Marc de Jonge (
27 Jul 1995 14:13:50 GMT

In article <3v7b8n$>, (Whittet) writes:
|> In article <3v62cg$>, says..

|> >Now I'm reading this from sci.geo.geology (which, BTW, what
|> >does any of this have to do with geology), and, being a
|> >geologist, I have to say that even if all the numbers and
|> >angles of the pyramid correlate to days in a decade and fleas
|> >on the pharoah's cat, so what? What does it prove?
|> Forget that, I have a geology question for you Jim. What hardness
|> on the mohr scale does it take to cut Diorite?

Well, as this question is more or less on-topic:

For a rough cut anything harder than the softest rock forming mineral of diorite
(probably biotite: 3) will do (you cut the soft mineral, the harder grains fall out
intact, but the rock is cut anyway).
For a smoother cut you can do it with a sharpened piece of the same diorite
(hardness x will cut hardness x, both wear out at about the same rate).

|> ( The Egyptians were supposedly using copper chisels)

The hardness is hardly relevant for chiseling. You only have to deliver
a lot of force to a small area, so although a copper chisel will get
blunt sooner than a steel one, it's entirely possible to chip away
a harder rock with it (by randomly breaking the crystals along their
cleavage planes).

|> Could they have used something like a powder or paste of some
|> semi precious gem as an abrassive with which to cut? What would
|> it have taken? A corrundum or would they have had to use diamonds?

They could have used that, but plain sand is sufficient.
Using a rope or steel cable and a few handfuls of sand you can cut through
any common rock (some small quarries use that method even now).

Marc de Jonge (