title: Vibrational spectroscopy and solubility study of the mineral stringhamite CaCuSiO₄·H₂O.
abstract: Stringhamite CaCuSiO(4)·H(2)O is a hydrated calcium copper silicate and is commonly known as a significant 'healing' mineral and is potentially a semi-precious jewel. Stringhamite is a neosilicate with Cu(2+) in square planar coordination. Vibrational spectroscopy has been used to characterise the molecular structure of stringhamite. The intense sharp Raman band at 956 cm(-1) is assigned to the ν(1) (A(1g)) symmetric stretching vibration. Raman bands at 980, 997, 1061 cm(-1) are assigned to the ν(3) (A(2u), B(1g)) antisymmetric stretching vibrations. Splitting of the ν(3) vibrational mode supports the concept that the stringhamite SiO(4) tetrahedron is strongly distorted. The intense bands at 505 and 519 cm(-1) and at 570 cm(-1) are assigned to the ν(2) and ν(4) vibrational modes. The question arises as to whether the mineral stringhamite can actually function as a healing mineral. An estimation of the solubility product at pH<5 shows that the cupric ion can be released. The copper ion is a very powerful antibiological agent and thus the mineral stringhamite may well function as a healing mineral.
authors.affiliation: Chemistry Discipline, Faculty of Science and Technology, Queensland University of Technology, GPO Box 2434, Brisbane, Queensland 4001, Australia. r.frost@qut.edu.au
authors.forename: Ray L
authors.initials: RL
authors.lastname: Frost
authors.forename: Yunfei
authors.initials: Y
authors.lastname: Xi
mesh_terms: D017610:Calcium Compounds / Q000737:chemistry*; D003300:Copper / Q000008:administration & dosage* / Q000737:chemistry; D017640:Silicates / Q000737:chemistry*; D012995:Solubility; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman
chemical_list: D017610:Calcium Compounds; D017640:Silicates; C047041:copper silicate; D003300:Copper