1. Run → Go draws the diagram Add any background ions Set temperature Select main species to diagram Choose axes Act2 generates stability diagrams on activity, Eh, pe, pH, and fugacity axes

2. Move to the Plot pane. Minerals plot in gold, aqueous species in blue You can copy the diagram to the clipboard and paste into your documents

3. Activity-activity diagram for the Cu-CO 2 -Cl system

4. f O 2 -pH diagram for Uranium

5. Choose pH for the x axis Run → Go draws the diagram Set temperature Set the main species as the y axis variable A solubility diagrams uses the activity of the main species as an axis variable

6. Gibbsite is very soluble at low and high pH

7. Mosaic diagrams account for the speciation of complexing ligands with pH and redox state Click on SO 4 2− unit pulldown and select “speciate over x-y”

8. Blue lines show speciation of the SO 4 2− ligand. New plot accounts for changing SO 4 2− speciation. Note how Orpiment and Realgar stability fields changed.

9. You can set activity or fugacity ratios, like H 2 S(g)/CH 4 (g). Tact makes temperature-activity and temperature-fugacity diagrams Temperature range

10. Equilibrium point of the methane souring reaction, calculated as a function of temperature. CH 4 (g) + Anhydrite ↔ Calcite + H 2 O + H 2 S(g)