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Natural alkali-rich aluminosilicates minerals from Harmancık/Bursa/Turkey and Kepsut/Balıkesir (Turkey) were characterised by X-ray diffractometry (XRD), X-ray fluorescence (XRF) and investigated the blue thermoluminescence (TL) emission of the samples. The TL glow curves exhibited a very complex structure that were analyzed via computerized glow curve deconvolution (CGCD), initial rise (IR) and variable heating rate (VHR) techniques. It could be appreciated how the kinetic parameters (trap depth - E a -, kinetic order – b- and frequency factor – s- for each electron trap levels) were consistent regardless of the analytical method used. • TL properties of natural alkali-rich aluminosilicates from Turkey were determined. • CGCD, IR methods were used to determine the number of peaks and kinetic parameters. • Aluminosilicate sample from Kepsut can be used as high dose dosimetric purposes. [ABSTRACT FROM AUTHOR]

We report structural, chemical composition, thermal decomposition and stimulated luminescence properties of a colemanite-rich borate (Ca 2 B 6 O 11 •5H 2 O) mineral collected from Kırka, Eskişehir region of Turkey. X-ray diffraction shows that the colemanite phase has a monoclinic crystal structure. Further, Raman spectroscopic analysis reveals that the sample contains 45.83% of B and 17.93% of CaO. Thermogravimetric analysis indicates that there is removal of hydroxyl groups followed by explosive release of water from the sample at temperature below 200 °C. The sample produces thermoluminescence (TL) and optically stimulated luminescence (OSL) following beta irradiation. A TL glow curve measured at 1 °C/s consists of five glow peaks at ∼145, 175, 215, 267 and 322 °C. The activation energy associated with the peaks are ∼0.73, 0.77, 0.83, 0.90 and 1.19 eV respectively and the frequency factors are ∼106 ‒ 108 s−1. The lifetimes of the traps at room temperature are estimated to be ∼1.42 days to 2.33 × 104 years. The peaks at ∼175, 215 and 267 °C show supralinear dose response between 32 and 16000 Gy whereas the ones at ∼145 and 322 °C show supralinearity between 32 and 2048 Gy. Analysis of the OSL decay curve shows that the decay curve has a 'fast'-, 'medium'- and a 'slow' component. The dose response of the fast component is found to be linear within 2–4096 Gy and that of the medium- and slow components are found to be superlinear between 2 Gy and 4096 Gy. • XRD, Raman, TGA, TL and OSL of a colemanite-rich borate mineral have been reported. • The sample contains 45.83% of B and 17.93% of CaO. • TL measured at 1 °C/s produces five glow peaks at ∼145, 175, 215, 267 and 322 °C. • There are five electron traps (E = 0.73, 0.77, 0.83, 0.90 and 1.19 eV). • OSL decay curve of the sample consists a fast-, medium- and slow-components. [ABSTRACT FROM AUTHOR]

Although naturally occurring luminescence materials such as quartz and feldspars are generally used for radiation dosimetry and dating, natural borates may also stand as a promising material for dosimetry and dating. We report thermoluminescence (TL) and optically stimulated luminescence (OSL) of one of the most abundant boron minerals in Turkey namely, ulexite (NaCaB 5 O 6 (OH) 6 ·5H 2 O). An X-ray diffraction (XRD) analysis confirmed that the sample has triclinic crystal structure and contains 40.55% of B, 5.92% of Na 2 O, 12.3% of CaO. A thermogravimetric analysis indicates two stages of dehydration within 60–160 °C, 160–250 °C and dehydroxylation within 260–580 °C. Analysis of TL glow curves using fractional glow and deconvolution reveal that there are four glow peaks at 154, 211, 273 and 327 °C in the glow curve of ulexite. All the glow peaks follow a non-first order kinetics. The activation energies of the traps are estimated from the fractional glow curves as 0.72, 0.93, 1.16 and 1.28 eV and that evaluated from the deconvolution analysis as 0.76, 0.83, 0.96 and 1.27 eV. The lifetimes of these traps are estimated within 1.55 days–3.6 × 104 years. The radiation dose responses of the TL peaks are supra-linear between 8 Gy and 1024 Gy. OSL decay curve of ulexite consists a fast, a medium and a slow component with recombination lifetimes of (0.63 ± 0.08), (7.51 ± 0.71), (93.49 ± 3.62) s respectively. The fast OSL component obeyed first order, whereas medium and slow components obeyed general order of kinetics. The dose response of the medium and slow OSL components showed a sub-linearity from 64 Gy to 4096 Gy whereas the fast component showed linear response between 8 and 4096 Gy. • TL and OSL of ulexite collected from Kırka, Eskişehir, Turkey have been reported. • There are four electron traps of activation energy = 0.72, 0.93, 1.16 and 1.28 eV. • Lifetimes of the electron traps are estimated around 1.55 days to 3.6 × 104 years. • OSL curve of ulexite consists a fast (C1), medium (C2) and a slow (C3) component. • Dose response of C1 is linear (8‒4096Gy) but that of C2, C3 sub-linear (64‒4096Gy). [ABSTRACT FROM AUTHOR]