Supports· weakGEO-E017
Multinuclear NMR reads Bent Pyramid casing stone as Tura grains in an artificial calcium-silicate gel
- what the source states
- Solid-state ²⁹Si, ²⁷Al and ⁴³Ca MAS NMR spectra of an outer casing stone from Snefru's Bent Pyramid at Dahshour, compared with two quarry limestones from the area, "suggest that the casing stones consist of limestone grains from the Tura quarry, cemented with an amorphous calcium-silicate gel formed by human intervention, by the addition of extra silica, possibly diatomaceous earth, from the Fayium area."
- what we infer
- An independent technique pointing the same way as GEO-E012 — but note the binder has changed: this is a lime-pozzolan C–S–H gel, not Davidovits' alkali-aluminosilicate geopolymer. Jana's decisive negative (no alkali-aluminosilicate signature, GEO-E020) therefore refutes the original recipe without touching this revised one; conversely, the pro-casting side's own evidence no longer supports the "geopolymer" claim as originally stated. Evidence against one binder chemistry does not automatically count against the other.
- limitations
- One casing stone and two quarry comparators; 'human intervention' is an interpretive step from spectra (the abstract says 'suggest').
- Barsoum is a co-author, so this is not fully independent of GEO-E012.
- No published independent replication, comment, or rebuttal specific to this paper was found (checked 2026-08-22).