TABLE 1. Mineral names and chemical formulae referenced in this work. Molar volume is given per formula unit. Deliquescent minerals are marked “del.”
| Formula | Vol pfu (Å3) | ||
| Aluminum sulfates | |||
| Halotrichite | Fe2+Al2(SO4)4 • 22H2O | del | 791.3 |
| Alunogen | Al2(SO4)3 • 17H2O | del | 595.5 |
| Ferrous sulfates | |||
| Szomolnokite | Fe2+SO4 • H2O | 90.9 | |
| Rozenite | Fe2+SO4 • 4H2O | 785.5 | |
| Melanterite | Fe2+SO4 • 7H2O | del | 243.9 |
| Ferric sulfates | |||
| Kornelite | Fe23+(SO4)3 • 7H2O | 387.5 | |
| Coquimbite | Fe23+(SO4)3 • 9H2O (idealized) | del | 440.6 |
| Coquimbite | Fe2-x3+Alx(SO4)3 • 9H2O (actual) | del | 440.6 |
| Quenstedtite | Fe23+(SO4)3 • 10H2O | 462.2 | |
| Fibroferrite | Fe3+(SO4)(OH) • 5H2O | 206.6 | |
| Rhomboclase | HFe3+(SO4)2 • 4H2O | 241.7 | |
| Mixed iron sulfates | |||
| Römerite | Fe2+Fe23+(SO4)4 • 14H2O | 611.7 | |
| Jarosite | (H3O),K,NaFe23+(SO4)2 (OH)6 | 264.9 | |
| Copiapite | Fe2+Fe23+(SO4)6(OH)2 • 20H2O | 1175.1 | |
| Sulfides | |||
| Pyrite | Fe2+S-2 (isometric) | 39.8 | |
| Marcasite | Fe2+S-2 (orthorhombic) | 40.7 | |
| Pyrrhotite | Fe(1-x)2+S (x = 0 to 0.2) | varies | |
| Calcium sulfates | |||
| Gypsum | CaSO4 • 2H2O | 123.8 | |
| Bassanite | CaSO4 • 0.5 H2O | 88.0 | |
| Anhydrite | CaSO4 | 76.4 | |
| Iron oxides | |||
| Hematite | Fe2O3 | 50.5 | |
| Magnetite | Fe3O4 | 74.0 |
TABLE 2. Stability of pyrite at elevated temperatures under a variety of atmospheres. DTA is differential thermal analysis, po is pyrrhotite, and py is pyrite. DTA peaks are the maxima of temperature for mineral transformation. Otherwise, the upper and lower brackets for the reactions are given.
| Reference | Atmosphere | Results | |
| De Oliviera et al. (2019) | N2 | 400°C py | 600°C po appears |
| De Oliviera et al. (2019) | CO2 | 400°C py | 600°C po appears |
| Thomas et al. (2003) | Argon | 635°C py to po DTA | |
| Zhang et al. (2019) | N2 in standard furnace | 665°C DTA peak | |
| Zhang et al. (2019) | N2 with microwave heating | Po appears at 500°C | |
| Huang et al. (2015) | CO2 | 560°C DTA peak | |
| Bhargava et al. (2009) | 10-3 bar O2 | 400-850°C No po | |
| Bhargava et al. (2009) | Air | 400°C py | 450°C hm, no py |
| Bhargava et al. (2009) | Argon | 500°C no po | 600°C po appears |
| Bhargava et al. (2009) | CO2 | 400°C no po | 500°C po appears |
| Charpentier and Masset (2010) | Argon+O2, 10-6 bar O 2 | Po above 550°C | DTA peak slightly above 600°C |
