Documentation
Minerals & species
The 10 scale minerals Crysalt evaluates and the 21 input species it accepts. These ids are the exact
strings used everywhere — the API, the MCP tools, and the /api/v1/metadata capabilities
endpoint, which serves this list live so a UI or an AI agent can build input forms dynamically.
Scale minerals
“K(P)” marks minerals whose solubility product is pressure-corrected (see Methodology).
| Id | Name | Formula | System | K(P) |
|---|---|---|---|---|
BaSO4 | Barite | BaSO₄ | Sulfate | ✓ |
SrSO4 | Celestite | SrSO₄ | Sulfate | ✓ |
CaSO4 | Anhydrite | CaSO₄ | Sulfate | ✓ |
CaSO4:2H2O | Gypsum | CaSO₄·2H₂O | Sulfate | ✓ |
CaCO3 | Calcite | CaCO₃ | Carbonate | ✓ |
FeCO3 | Siderite | FeCO₃ | Carbonate | — |
FeS | Iron sulfide | FeS | Sulfide | — |
ZnS | Sphalerite | ZnS | Sulfide | — |
PbS | Galena | PbS | Sulfide | — |
NaCl | Halite | NaCl | Halide | ✓ |
Calcite's polymorphs aragonite and vaterite are tracked too: at equilibrium only calcite precipitates, so they are reported as supersaturation (SR/SI) diagnostics rather than as forming solids.
Input species
Concentrations are entered in mg/L. Charge is shown for reference (0 = neutral).
Cations
| Id | Charge |
|---|---|
Na+ | +1 |
K+ | +1 |
Ca2+ | +2 |
Mg2+ | +2 |
Ba2+ | +2 |
Sr2+ | +2 |
Fe2+ | +2 |
Zn2+ | +2 |
Pb2+ | +2 |
H+ | +1 |
Anions
| Id | Charge |
|---|---|
Cl- | −1 |
SO42- | −2 |
HCO3- | −1 |
CO32- | −2 |
HSO4- | −1 |
HS- | −1 |
OH- | −1 |
Br- | −1 |
Dissolved gases (neutral)
| Id | Charge | Drives |
|---|---|---|
CO2 | 0 | Carbonate scaling (CaCO₃) & pH |
H2S | 0 | Sulfide scaling (FeS/ZnS/PbS) & pH |
CH4 | 0 | Scale-inert (enters the gas-mixture fugacity) |
Two things to know.
H+ and OH- are set by the pH input — you don't
pass them as composition. And Fe2+, Zn2+, Pb2+ and the dissolved
gases have no Pitzer interaction parameters in the shipped set, so they take γ = 1 (reliable at
low–moderate ionic strength) — see Methodology.