THE “MINFORM” APP: A 21ST CENTURY APPROACH TO MINERAL FORMULA CALCULATION

Calculating chemical formulas from mineral chemical data is an important skill taught in most undergraduate mineralogy courses. Too often, students are confused and overwhelmed by the tedious nature of the process, and as a result, fail to get a solid understanding of this important concept. In the past, mineral calculations were accomplished in one of two ways: by hand, or by using spreadsheets. While spreadsheets reduce the tedious nature of the process and minimize problems arising from human error, they often are very inflexible, with limited choices for data entry and processing options.

We have created a cross platform desktop application, “MinForm”, an app that calculates mineral formulas from weight percent oxide data input from either a spreadsheet, or by manual entry. The app provides greater flexibility than most spreadsheets by providing options for different assumptions that can be used when calculating mineral formulas. For example, options include charge-balance for iron, normalization based upon numbers of anions or cations, corrections for the presence of H2O, etc. The app also calculates proportions of mineral group end-members, and displays these graphically. In addition, all of the input data and calculated formulas can be easily exported and saved as a .xls file.

For each mineral group there is an option for entering a single mineral analyses and for displaying the step-by-step calculation of the mineral formula. This option allows students to examine the process in more detail, which enhances their understanding. It also allows students to identify where they made mistakes in any calculations that they did previously by hand.

Using Electron.JS as the base of the calculation software, the app overcomes some of the limitations of previous calculation methods. The “MinForm” app allows for rapid and flexible calculation of mineral formulas, and provides a new vehicle for teaching this skill and concept.