Tools for Petrologists

Excel Spreadsheets

WetMelts Conversion Tool
Excel spreadsheet with VisualBasic macros. Tool for converting anhydrous composition of a silicate melt in wt% plus known mol fraction of volatiles in the melt (H2O and CO2 mixture) to a hydrous melt composition in terms of both wt% and mol fraction. I created this tool as part of an independent study during my undergrad. Also see the tutorial.

WtpertoMolper Conversion Tool
Excel spreadsheet with VisualBasic macros. Tool for converting (hydrous or anhydrous) melt composition from wt% to mol%.

Oxide to Element Conversion Tool
Excel spreadsheet that will convert compositions measured in oxides (SiO2, FeO, K2O, etc) to elements (Si, Fe, K, etc), and vice versa.

Glass Density Calc
Excel spreadsheet. Input the composition of a silicate glass/melt in terms of wt% and the H2O content in terms of wt% plus the temperature and pressure of the sample. Spreadsheet outputs the density of your glass/melt in terms of g/cm³ and g/L. User inputs go in blue boxes, output is automatically generated in red boxes.
References: Lange & Carmichael (1990); Ochs & Lange (1999); Also see Hack & Thompson (2011)

fO2 Calculation
Excel spreadsheet. Tool for calculating the ferric/ferrous iron ratio in a melt for any given fO2. Also calculates new wt% values for FeO and Fe2O3 in your melt. Useful for determining theoretical iron speciation when total is given as FeOtotal or Fe2O3total and fO2 is known.
References: Kress & Carmichael (1991); B. R. Frost in Mineralogical Society of America “Reviews in Mineralogy” Volume 25.

Water From Iron Reduction
Excel spreadsheet. Great for experimental petrologists. If a silicate melt is “fused” or “pre-melted” at the same oxygen fugacity that the experiments are ultimately run at, the ratio of ferric to ferrous iron in the melt will remain unchanged. If, however, the melt is fused in air and then run at more reducing conditions, some of the Fe2O3 will be reduced to FeO and will add water to your melt in the process. Use this tool to calculate just how much water was added to your melt due to the reduction of iron during your run. Only works if pre-run fO2 is in air (i.e. all iron is Fe2O3 before run), but calculation can be made for any experimental fO2.
References: Kress & Carmichael (1991); B. R. Frost in Mineralogical Society of America “Reviews in Mineralogy” Volume 25.

Link: Gabbrosoft Mineralogical Spreadsheets
Spreadsheets for calculating mineral formulas based on an electron microprobe analysis. The spreadsheet does all the hard work, so you don’t have to! Also find the Bulk KD calculator for calculating trace element bulk KD values given the mineral make-up of a sample, and the Magma Density calculator for calculating the density of a magma from its major element composition.

Link: Mineral Formula Calculations
Various excel spreadsheets from Carlton College. Useful tools for calculating formulas of various mineral types based on electron microprobe or EDX measurements (or anything where you have an analysis of a mineral in terms of wt% oxides).

Link: Lots ‘o Petrologic Software from North Dakota State University
Software, spreadsheets, graphic programs, more. A list of all kinds of geologic (and petrologic) calculations, kindly hosted on the NDSU website.

Models Available Online

Some of my favorite models, none of which are by me but all of which are used by me!

Papale model for H2O-CO2 partitioning/solubility in magmas
Calculate isobars, fluid/melt partitioning, saturation pressures, solubilities! Calculations straight from the model of Papale P, Moretti R, Barbato D (2006) The compositional dependence of the saturation surface of H2O + CO2 fluids in silicate melts. Chemical Geology 229, 78-95.

VolatileCalc
This software calculates H2O-CO2-melt equilibrium for the rhyolite and basalt systems. The software is written as Visual Basic for Applications Macros within Microsoft Excel. Calculations from the model of Newman, S., Lowenstern, J.B., 2002, VolatileCalc: a silicate melt-H2O-CO2 solution model written in Visual Basic for Excel: Computers and Geosciences vol. 28 no. 5, pp. 597-604.

MELTS
MELTS is a software package designed to facilitate thermodynamic modeling of phase equilibria in magmatic systems. It provides the ability to compute equilibrium phase relations for igneous systems over the temperature range 500-2000 °C and the pressure range 0-2 GPa.

Model for Viscosity of Volatile-bearing Melts
From the paper Viscosity of magmatic liquids: A model by Giordano D, Russell JK & Dingwell DB (2008). Calculate the viscosity of a melt given composition, temperature, and H2O. The link above is a version of the model in javascript. There is also an Excel spreadsheet version.