## Sunday, May 5, 2019

### Mineral formula calculator: up and running

Adularia.app is a simple web-based application that calculates mineral formulas based on the results of chemical analysis. The application was made in collaboration with a group of my friends, Peter Frolov and Nikita Krupnik, in attempt to simplify and exemplify mineral formula calculations that are usually done in MS Excel. It should also help undergraduate students that are often tasked to perform the calculations on paper by hand. This application could be used to check the results of such calculations.

It features two ways of calculating mineral formulas. One is anion-based method that uses prior knowledge of how many oxygens (and other negatively charge ions) are present in the formula. For example, in the formula of olivine, Mg2[SiO4], 4 oxygens. Imagine a grain of olivine was analyzed by electron microprobe yielding 42.06 % MgO, 18.75 % FeO and 39.19 % SiO2. Knowing that the mineral has 4 units of oxygen, the rest of the formula will be calculated as Mg1.6Fe0.4[SiO4]. See this implemented in the screenshot.