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Table 3 Inorganic compounds detected by XRD in the samples

From: Comparative chemical investigations of alum treated archaeological wood from various museum collections

Collection Sample Major compounds Minor compounds
Dejbjerg D-A1624 K-alum Alunite, gypsum
D-B1624 K-alum Syngenite
D-C1628 K-alum Syngenite
D-D1626-A K-alum Syngenite
D-D1626-B K-alum  
D-E1622-A K-alum Gypsum
D-E1622-B K-alum  
D-F1629 K-alum  
Oseberg N-187D K-alum, Mercallite  
N-187L K-alum Mercallite
N-207-A NH4-alum  
N-207-B NH4-alum  
N-250F K-alum  
N-250K K-alum, alunite  
Glimmingehus S-5T K-alum  
S-125ha   Alunite
S-125k K-alum Alunite
S-346d K-alum, alunite Syngenite
S-346e K-alum Alunite, syngenite
S-383 K-alum Mercallite
S-383c K-alum Mercallite
  1. ‘Major’ and ‘Minor’ refer to the intensity of crystalline peaks in the XRD patterns, which only reflects their relative abundance, and does not reflect the abundance of these compounds relative to the wood material or other amorphous components. ‘Major’ patterns showed intense, clearly defined peaks, such as those seen in Figs. 1 and 2. ‘Minor’ patterns generally appeared as small peaks that were difficult to distinguish from the baseline, relative to the more intense ‘major’ pattern, but could be unambiguously identified as the assigned compound using the software and were consistent with elemental compositions observed by SEM–EDS. Chemical formulae for minerals: K-alum = KAl(SO4)2·12H2O; NH4-alum = NH4Al(SO4)2·12H2O; alunite = KAl3(SO4)2(OH)6; gypsum = CaSO4·2H2O; syngenite = K2Ca(SO4)2·H2O; mercallite = KHSO4
  2. aSamples re-treated with PEG 2000 between 2005 and 2009