GEMS Tutorials

Start with the tutorial pdf files below for instructions, and copy each of the tutorial project file folders to your gems project library folder (Library\Gems3\projects). Start with Module 1 to learn about project and resource folder locations and get started with GEMS. The entire tutorial package can also be downloaded here as a .zip file with solved/unsolved problems (for workshop).

In Module 1, you will learn to copy/paste the MINES database to your GEMS resource folder, and how to create a new project from scratch. In Module 2, you will model the hydrolysis of feldspar. In Module 3, you will learn how to add a rock and a fluid, and simulate titration and greisen alteration. In Module 4, we will continue the greisen alteration model and simulate a multipass and single cooling models. In Module 5, you will learn about GEM2MT to simulate a reactive mass transport problem in MVT type deposits. To run these tutorials you will need to download and install the latest GEM-Selektor.


  • Module 1 (pdf): Installation MINES database and first project
  • Module 2 (pdf): K-feldspar reaction path
  • Module 3 (pdf): Greisen alteration (Part I), titration model, adding a fluid and a rock
  • Module 4 (pdf): Greisen alteration (Part II), multi-(leaching) and single-pass (flushing) cooling models
  • Module 5 (pdf): Reactive mass transport using the GEM2MT module, mineralization of Pb-Zn in MVT deposit

Tutorial Project Files

Alexander Gysi

Assistant Professor, Lithogeochemistry
Department of Geology and Geological Engineering
1516 Illinois Street
Colorado School of Mines
Golden, CO 80401

GEMS code package

The GEMS code package provides a free versatile geochemical tool taking advantage of modern computational methods and the Gibbs energy minimization (GEM) method. The core of GEMS includes the GEMS3K numerical kernel capable of solving fluid-rock equilibria problems at elevated temperatures and pressures in highly non-ideal systems. GEMS3K is a chemical equilibrium speciation solver for modeling multiphase-multicomponent geochemical equilibria using the GEM algorithm, with a built-in selection of activity models and equations of state in the TSolMod class library. This library includes a comprehensive selection of fluid, gas, liquid, and solid solution models of interest for geochemical, petrological, material science, and chemical engineering applications. The GEMS3K kernel is also implemented in the GEMSFITS code for parameter optimization of internally consistent databases, and in the user friendly program GEM-Selektor v.3.3.


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