ESR dosimetric properties of talc and zircon

Two silicate minerals talc (Mg₃Si₄O₁₀(OH)₂) and zircon (ZrSiO₄) with different crystal lattice structures were subjected to ESR dosimetric studies. Zircon shows anisotropic ESR signals at g_xx = 2.0168, g_yy = 2.0076 and g_zz = 2.0033, which have been identified as a hole-center associated with Y³⁺ substituted at Zr⁴⁺ sites. Other characteristic signals were observed and identified. The ESR signal at g = 2.0033 showed positive response to γ-irradiation at 110 Gy and is suitable for use in dosimetry and dating of natural zircons.Talc (a magnesium sheeted silicate) exhibits ESR derivative spectrum characterized by the presence of Fe³⁺ at g = 4.28 and the hf-sixtet Mn²⁺ signals. This is due to the possible substitution of Fe³⁺ and Mn²⁺ in the Mg²⁺ octahedral sites, respectively. The enhancement of the Mn²⁺ sixtet by γ-irradiation increases the area occupied by the signals that makes it difficult for use with dosimetric applications.