<HTML>To All,
Below is the explanation of geopolymeric Egyptian faience -- made at moderate heat and so it matches the chemical analysis of Zoser's tiles, etc. Without fusing quartz!
I'll preface what I have to say with this remark. When I first came across this board I was hoping to find someplace on the net where Dr. Davidovits might hold a special session with non-technical people who care about Egyptian antiquity and want to learn the basics and be able to ask questions (his own forum is for technicians). Katherine's home on the net looked like a good place. I was disgusted when I saw Davidovits's work being misrepresented and abused on this board and at Blease's place.
Now I doubt seriously that Dr. Davidovits would ever consider holding a special session here because there's been so much disrespect paid toward him and people have shown over and over that they don't read the primary literature. Instead they just imagine anything -- based on distortions and assumptions -- and then think they've disprove Davidovits or knocked his work down a few notches.
Why should he hang with people who don't understand how due process is supposed to work in science or have the training to appreciate data or at least be respectful of the potential importance of data? I think a wonderful opportunity has been blown.
I make my remarks above because I can't tell you what goes on in his lab when he makes Egyptian faience. I do understand the basic principle of how to make geopolymeric Egyptian faience at moderate temperatures -- which is enough to satisfy Frank's challenge to me. Frank has refused to believe Egyptian faience is geopolymer and has been claiming to have disproved it with his recent posts about melted quartz. Now Frank asks for an explanation.
And before I explain everybody should remember what Frank said about Predynastic Egyptians having had high temperature (in the post to which this replies). I mention this not to dig at Frank but because it's relevant to the main point about faience production with moderate heat.
Frank's books tell him high temperatures were needed for the first copper smelting. Frank has used this assumption to then make the leap that high heat must have been known to Predynastic Egyptians. On the other hand, Egyptology has established that the hand bellows was not invented until later for fanning fires to raise their temperatures.
Frank making his leap of faith is like saying the pyramids exist therefore they must be carved rock because that's how we'd do it today because the blocks are real limestone. The entire premise can be overturned with the right knowledge.
Likewise, the first extraction of copper ore did not require high temperatures. Turquoise is a copper ore from the Sinai. As explained by Dr. Joseph Davidovits, turquoise will fuse easily when natron is added to it when firing. Davidovits says that using caustic soda (natron + lime + water) will lower the fusion point of certain copper ore like chrysocolla even more (the info I'm drawing from is not about copper smelting but about how to make blue enamel at moderate heat -- so I'm not going to extrapolate here concerning the first Predynastic copper smelting). Too bad the opportunity to try to get Dr. Davidovits here for a special session to clarify this matter has been blown by the rudenicks.
Anyway, anyone can read Lucas's pages and see that blue enamel on faience, etc. is a glassy substance, and everyone assumes that glass requires high temps. The reason is that today we do this by fusing sand.
So without the benefit of Dr. Joseph Davidovits's firsthand experience I will explain how he makes Egyptian faience without those high temperatures. My explanation comes from what I've drawn from the writings of Margaret Morris and Joseph Davidovits -- my learning is just the tip of the iceberg compared to what is documented in Davidovits's vast body of technical literature.
To understand Egyptian faience we first have to appreciate that it was thought to be real sandstone by experts because of its quality and that experts fought a long battle before Egyptian faience was proved to be synthetic. When we appreciate this we understand that the Egyptians began making "sandstone" (Egyptian faience) all the way back about 4000 BC -- before Egypt became a nation! The knowledge establishes foundation knowledge for making synthetic pyramid stone later on (this will become clear below).
Here's a quote from Davidovits and Morris (1988, page 241) that tells part of the story of how early Egyptologists thought Egyptian faience was real sandstone (as did Le Chatelier at first, before he proved otherwise). Le Chatelier said:
"The basic material of which the statuettes are made is fine angular grains of sand, indicating careful grinding. Some claim that this indicates that the objects were carved of natural sandstone and enameled. I have shown that the statuettes contain numerous spherical bubbles, which means that, irrefutably, they are made of an artificial ceramic matrix."
Le Chatelier was here talking about really ancient Egyptian faience from the Thinite period. He also studied samples from Zoser's pyramid and made chemical analyses. His charts show that for the most part Egyptian faience is silica. He lists total silica at between 93 and 95 %. Then there's iron oxide at a negligible % of .1 or less. There's aluminum oxide at 1 to 2.5 %. There's lime at .6 to 1.7 %. There's magnesium at .04 to .08 %. There's soda at .6 to 2.5 %.
(As shown below, the substances important for geopolymerization in this group are the soda [natron], lime, alumina and part of the silica.)
When Le Chatelier tried to reproduce the faience from the above list of substances in his chemical analysis he couldn't do so. He mixed clay at 10 %, ground sand and coarse sand at a combination of 90 %. His assumption that clay provided the aluminum meant that his formula had twice as much aluminum as the samples of Egyptian faience. This showed Le Chatelier his formulation does not represent the way the AEs made their Egyptian faience.
Clay is not in the formula the Egyptians used. Le Chatelier's detractors used this against him to insist that the Egyptian faience statuettes are natural sandstone. They assumed no "ceramic" could be made without clay.
Frank D's books tell him that to make Egyptian faience silica is fused and everyone knows that silica in the form of quartz requires 2370 F or 1300 C to fuse. On the other hand, Egyptologists know that Predynastic people could not achieve these temperatures. This is just one of those many mysteries of Egyptology taken for granted these days. The problem is solved by geopolymerization.
About 30 years ago Dr. Joseph Davidovits discovered the chemistry of geopolymerization. After he began his research on ancient Egypt he showed that what is key to making the Egyptian faience is the small amounts of aluminum and silicate (see Le Chatelier's analysis above). Turquoise contains aluminum and chrysocolla contains a hydrous silica. Both are found in the Sinai and were mined to a great extent starting in early times.
To make geopolymeric faience, natron is added to lime and water to form caustic soda. Unlike quartz, caustic soda reacts with hydrous silicas (like flint, opal, agate, onyx, chrysocolla, puddingstone, etc.), at far lower temperatures, between 122 F and 302 F or 50 C and 150 C! The reason is that rather than having a compact structure like quartz, hydrous silica contains water in its structure.
Compare the major difference in temperatures:
Between 122 F and 302 F to fuse hydrous silica
About 2370 F to fuse quartz!
Using caustic soda to fuse hydrous silica causes sodium silicate to form. When an aluminum phosphate like turquoise is added to this sodium silicate, zeolites form. In other words, geopolymerization has taken place!
The zeolites produced are feldspar minerals, like feldspathoids. When feldspathoids are heated, they convert to feldspar.
Anyone reading this should be able to begin to see the potential: Synthetic zeolites (feldspar minerals like feldspathoids) are formed. Feldspathiods are transformed into feldspar when heat is applied, and this is the basis of many natural cements that bind natural rocks. Geopolymerization produces a zeolitic binder equivalent to natural cements.
(Although Dr. Davidovits doesn't talk about this in his discussion whereas MM does-- this needs to be kept in mind relative to the feldspar in granite that Chris Dunn thinks was cut through by machines. Instead, the feldspar could be the product of geopolymerization -- feldspar crystals cut with simple tools while still in a partially cured state. The zeolitic material can also be molded or used to make molds (see the info about Dr. Davidovits industrial molds posted on this board or Margaret Morris v Chris Dunn on this board for how molds can be made with zeolite crystals of 5 micron size that produce flat surfaces of .0002 inch. Much smaller zeolites exist. Zeolites can be nanosized).
There are many ways to make crystals with geopolymerization. It is interesting that adding burnt cereal grains yields opal ct, which transforms gradually to quartz. This means that when quartz is found in AE Old Kingdom or earlier artifacts it has to be specially studied if the geopolymer question is being considered.
To summarize geopolymeric Egyptian faience, adding water to natron and lime produces caustic soda. Caustic soda acts as an alkali that will attack amorphous silicas (like the kaolin clay at Giza) with no heat. This leads to the production of pyramid limestone. Just throw lime and natron in the quarries and let the water in during the flood season so the kaolin will be attacked by the resulting caustic soda (Morris advised FD to go look up Diodorus).
Caustic soda will attack hydrous silicas (like flints and agates, etc.) at moderate heat (between 122 F and 302 F). So here we have a form of silica -- ready to be reacted with alumina (from turquoise) to form a geopolymer (a silico-aluminate zeolite). This system has nothing to do with fusing quartz.
Quartz will appear in Egyptian faience because the product is made with sand as an aggregate--but this quartz has not fused and it's not part of the geopolymeric chemical reaction.
I have explained the principle of moderate temperature geopolymeric Egyptian faience above. Frank has agreed to listen now that he's seen a little light from my recent posts.
It would appear that Frank has finally extended an olive branch.
Perhaps he is ready to recognize that textbooks are rewritten every day of the week as science advances. As such, I think he should shut down the portion on geopolymers at his web site pending proper investigation of this theory. What he has there now amounts to misinformation about geopolymerization.
I close by strongly stressing that we are dealing here with an entirely new body of science and a new paradigm both at once. No one can make assumptions (as has been repeatedly done on this board and elsewhere) because thinking within new paradigms can be very challenging. Often times our old thinking is inadequate for understanding new paradigms and new bodies of science. Geopolymerization presents both -- but it's not beyond our grasp.
Sandy J. Perkins</HTML>
