Supports· moderateGEO-E012
SEM/TEM microconstituents in pyramid samples read as reconstituted limestone (Barsoum 2006)
- what the source states
- SEM/TEM comparison of pyramid limestone samples against six natural limestone sources from their vicinity found microconstituents with appreciable Si in combination with Ca and Mg "in ratios that do not exist in any of the potential limestone sources"; hydrated phases with calcite/dolomite-like chemistries "not known to hydrate in nature"; and amorphous or nanocrystalline Si-containing phases consistent with relatively rapid precipitation from a basic solution. The authors claim this for some samples only, and expressly acknowledge that nature "could have — however unlikely — produced all the microstructures examined herein."
- what we infer
- The strongest single pro-casting dataset and the only non-proponent laboratory support in the corpus. Its features are real observations; what is disputed is their diagnosticity, since the subsequent petrographic literature (GEO-E018–E021) reports the same classes of features in undisputed natural limestone.
- limitations
- Sample provenance contested: Egypt's Supreme Council of Antiquities stated no sampling permission was granted and the samples' origin is unknown (Hawass, quoted Dec 2006).
- Six-quarry comparison set may not exhaust natural limestone variability.
- No independent replication of these anomalies on provenance-secure samples exists.
- No formal comment/reply exchange on this paper exists in the journal; the critical response ran through the 2007 ICMA proceedings (Jana; Freestone & Middleton) and the earlier 1991–93 letters cycles, so the record must be assembled across venues rather than read from one exchange.