The waterglass question
Janna James over at Funny Olde World put up a video called "The Forgotten Secret to Making Stone." I watched it this morning as a warm-up and it sent me down a chemistry rabbit hole with my co-engineer.
She is chasing Marcell Foti's Natron Theory — the claim that the ancient Egyptians didn't quarry every pyramid block, they cast some of them, using a chemistry that has been sitting in plain sight the whole time.
The mechanism she lays out:
- Melt natron — sodium carbonate — at about 851°C in a small on-site furnace with a chimney.
- Pour it over granite. It etches the silicate minerals that bond the stone, and the granite starts breaking down into individual mineral grains.
- Left behind on the stone surface as residue is water glass — sodium silicate — a white powder.
- Scrape the water glass, mix with water, wood ash, slaked lime, and whatever powdered stone you want to reconstitute.
- It sets. Rock hard. Video claims Mohs 6.5 — harder than steel.
I brought the whole thing to Claude and asked what happens when the chemistry gets actually run against this claim, not just repeated or dismissed.
What holds up
The core reaction — Na₂CO₃ + SiO₂ → Na₂SiO₃ + CO₂ — is real. It is the alkali fusion technique analytical labs use today to dissolve silicate rocks for elemental analysis. Feldspars and quartz in granite both react given enough heat and time. Sodium silicate genuinely forms as residue.
Sodium silicate — water glass — is a real industrial binder. Available in hardware shops like Janna says. Used in kiln linings, foundry sand cores, silicate concretes. Cured composites reach compressive strengths of 30 to 80 MPa, comparable to modern concrete. Mohs 6.5 is plausible for a well-cured silicate composite. Quartz is 7. This isn't magical hardness. It is what sodium-silicate binders actually do.
And here is the piece that made me sit up.
The peer-reviewed cousin to Foti's proposal is Barsoum, Ganguly, and Hug (2006), "Microstructural Evidence of Reconstituted Limestone Blocks in the Great Pyramids of Egypt", published in the Journal of the American Ceramic Society. They sampled actual pyramid blocks and reported submicron silica spheres and unusual Si-Ca-Mg ratios that don't match natural limestone. Submicron silica spheres are exactly the microstructural signature you would expect from a cured sodium-silicate binder residue.
Foti's mechanism and Barsoum's evidence are looking at the same material from two directions and pointing at the same answer.
The waste is already there
Here is the part that turns the theory from exotic to logical.
They were already cutting stone. Whatever else the pyramids required, the base structure and the core blocks needed shaping, dressing, squaring. Every one of those cuts, on the scale of the Great Pyramid, produces mountains of stone dust and offcuts. Ancient copper-and-abrasive cutting is not a clean operation. You end up sitting on tonnes of powdered stone as a byproduct whether you planned to or not.
Which means one of the standing objections to cast-stone theories — "why go to the effort of producing all that aggregate?" — quietly disappears. They didn't have to go to any effort. The aggregate was the waste. The question flips from "why would they do this?" to "what else would they do with it?" Reaggregating quarry waste into usable blocks is basic material economics. It is what you would do if you were sitting on a mountain of the stuff and had a binder that worked.
Foti's mechanism doesn't ask ancient Egypt to invent a new process to generate feedstock. It asks them to close a loop that was already there.
And the identical-copy problem dissolves too
Here is a second consequence that falls out for free.
Egyptology has a long list of "how did they make so many identical things?" puzzles. The mass-produced-looking canopic jars. The standardised sarcophagi. The Saqqara vessel hoards — tens of thousands of hard-stone bowls worked to sub-millimetre precision in diorite and granite. The pharaoh statues that repeat across sites with the same face, the same proportions, the same details. Every one of them requires the assumption of teams of exceptionally skilled carvers hand-producing identical work over and over.
Cast stone changes that arithmetic in one move. If you can pour a slurry of aggregate and binder into a mould, identical copies aren't a mystery — they are what the technology does by default. The original still needs to be sculpted once. Every copy after that is a moulding operation.
You don't need one master carver producing a hundred perfect statues. You need one master carver producing one perfect original, and then a mould crew.
Same shift as with the aggregate. The theory doesn't ask ancient Egypt to be exceptional in the ways mainstream Egyptology has been forced to make them exceptional. It asks them to be practical in the ways humans have always been practical.
And once the shape of the question is on the table — abundant local material, a natural binder, a mould — the mind wants to run it against other unexplained megalith sites. Easter Island's Moai in particular carry the right smoke: partial burial patterns from recent excavations, statue counts a small population shouldn't have managed, and a different chemistry cousin ready to hand (pozzolanic cement, the Roman-concrete family, made from the volcanic tuff and lime already on the island). That is its own investigation, another day.
What still needs testing
The chemistry stands. The archaeology is where the load-bearing questions live.
Scale. Janna herself flags this — around 4 million logs of wood for plant-derived natron at full pyramid scale. Dynastic Egypt was already deforesting. Mineral natron from the Wadi Natrun is more plausible for scale, but the extraction and transport numbers still need working properly.
Infrastructure. No archaeological trace has been documented for the on-site melting furnaces the theory requires. Small chimney rigs pouring molten sodium carbonate over bedrock should leave a footprint — thermal alteration of the underlying stone, ash residues, ceramic fragments. Not saying they don't exist. Saying we would want to look with the right eye for it.
Tool marks. The video reinterprets quarry marks at Aswan as alkali-etching signatures. That is a specific claim. Direct petrographic comparison of documented Aswan tool-mark morphology against known alkali-etch surface signatures is a test that would move the needle either way.
Durability. Sodium-silicate binders are famously moisture-sensitive over long timescales. Alkali-silica reaction with certain aggregates causes degradation over decades. Pyramid casing stones have survived millennia. If this were the mechanism, the specific formulation would have to be exceptional. Worth understanding what makes it so.
Where this leaves me
Foti's chemistry is real. Barsoum's evidence is real. The full theory sits somewhere between "not proven" and "not addressed" by mainstream Egyptology — mostly the latter, which is not the same as "refuted." When peer-reviewed evidence exists and the mainstream response is to ignore rather than engage, that is an unfinished conversation, not a closed one.
I am not saying the pyramids were cast. I am saying the specific chemistry claim in Janna's video is not fringe pseudoscience. It is alkali fusion and industrial sodium silicate — both well-documented, both plausible mechanisms for a subset of the pyramid stone, and both consistent with the strongest published anomalies in actual pyramid samples.
The honest scientific position is: untested at pyramid scale, worth testing, and the tests are specific and doable.
That is a better place to leave a theory than most.
Video: "The Forgotten Secret to Making Stone" — Funny Olde World / Janna James Peer-reviewed cousin: Barsoum, Ganguly, Hug (2006), Journal of the American Ceramic Society Foti's site: natrontheory.com
Chemistry chased at indigo-nx.com.