Effects of Calcination on the Crystallography and Nonbiogenic Aragonite Formation of Ark Clam Shell under Ambient Condition

Figure 5

IR absorption spectra of ACS after calcination at 400–1400°C for 3 hours and cooling down with −10°C min⁻¹, which were kept under ambient condition for three months (C = bonds of calcite; OH = O–H and Ca–OH₂ bonds of water; H = Ca–OH in Ca(OH)₂; and O = Ca–O bond in CaO).