Channel-Water Molecular Pattern and ¹H,²³ Na NMR Spectra Representation in Synthetic Red Beryl

The VU, IR and NMR testing methods are employed in this paper to investigate the coupling relationship between the channel water molecular pattern and the Na⁺ in the channels of beryls including the hydrothermal synthetic alkaline poor red beryl and the natural alkaline-rich or alkaline-poor beryl. The results show that type I and type II channel-water molecules coexist in alkaline-poor synthetic red beryl though the abundance of type I channel-water molecule is distinctively dominant. ¹H NMR spectra, classified as the two typical spin systems, belong to two independent resonant signals respectively. The central NMR spectral peak (δ =1.7×10 ^-6) is related to Be-OH-Al, characteristic of type I channel water molecules. The associated NMR spectral peak (δ = 4.9×10 ^-6) is related to H-O...Na, characteristic of type II channel-water molecules. The chemical displacement of the central NMR spectral line of ²³ Na shows a regular change with the increase in Na ion concentration in channels, characterized by the deviation of the ²³ Na NMR spectral peak from the high magnetic field to the low magnetic field, the increase in split intensity and the decrease in split distance and semi peak width.At the same time, ¹ H NMR peak shape is transformed from the bi-spin system into the mono-spin system, indicating a conspicuous coupling relationship between the channel-water molecules and alkaline metal ions of the synthetic red beryl.