Study on the Experimental Conditions of Quantitative Analysis of Turquoise by Electron Probe

Turquoise is a kind of precious gem. Electron probe is often used to study the mineral components and distribution of turquoise in micro-zone non-destructive analysis. Natural turquoise not only contains crystal water and structural water, but also often contains unquantified adsorption water due to the pore development. Therefore, it is easy to cause the inaccuracy of the quantitative analysis results of turquoise electron probe test, and the total amount is low. In addition, the selection of standard samples and test conditions is also very important to the test results. So far, no relevant research has been found on the influence of different test conditions on the results of quantitative analysis of turquoise electron probe test. In this paper, Shimazu electron probe (EPMA-1720) was used for quantitative analysis of turquoise. By setting different acceleration voltage, beam current and beam spot diameter, the influence of different test conditions on quantitative results was analyzed, and the optimal quantitative analysis conditions of turquoise were obtained. The results show that when the acceleration voltage is 15 kV, the beam current is 10 nA or 20 nA, and the beam spot diameter is 1 μm, and the range of total turquoise measured is 79.95%-81.23%, which is close to the theoretical total turquoise 79.88%-81.35%, and the test result is the best. This experiment aims to establish a set of optimal test conditions suitable for quantitative analysis of turquoise electron probe test, which has certain reference significance and application value.