WIP Weathering Index Calculator

1. Enter major oxide values, especially Na₂O, MgO, K₂O, and CaO*.
2. Add SiO₂ and Al₂O₃ if you want a better normalization basis.
3. Choose dry or wet normalization, depending on LOI treatment.
4. Set the normalization total (commonly 100%).
5. Press Submit to calculate and show results above the form.
6. Use the CSV or PDF buttons to export a report.

Geochemical Interpretation Context

Weathering index calculations give laboratories a consistent way to compare chemical alteration across rocks, saprolites, and soils. The WIP method emphasizes mobile base cations, making it practical for screening silicate weathering intensity from oxide reports. Teams often combine this metric with petrography, loss on ignition, and immobile element ratios to strengthen interpretation. Used this way, WIP supports field logging, core interval ranking, and quality reviews across sampling programs in exploration and mine settings.

Operational Value in Laboratory Workflows

In busy analytical environments, repeatable data entry and rapid outputs are essential. This calculator standardizes major oxide inputs, applies optional normalization, and returns a formatted result above the form. That layout helps analysts review values before exporting. The built in table also supports internal checks during shift handovers. By reducing spreadsheet manipulation, laboratories lower transcription risk, preserve calculation consistency, and produce traceable records for technical reviews and audits.

What the WIP Result Indicates

Higher WIP values generally indicate fresher material because sodium, potassium, magnesium, and silicate calcium remain less depleted. Lower WIP values usually point to stronger chemical weathering, leaching, or prolonged alteration. However, interpretation should consider lithology, grain size, and alteration style. Mafic and felsic rocks can start with different oxide proportions, so direct comparison may mislead. The most reliable practice compares similar materials within the same project framework and sampling protocol.

Data Quality and CaO* Considerations

The CaO* term is critical because WIP assumes calcium represents the silicate fraction. If carbonate calcium is included, the index can be overstated, making weathering appear weaker than it truly is. Laboratories should document how CaO* was estimated, whether through carbonate correction, mineralogical screening, or supporting carbon measurements. Analysts should also confirm reporting basis, unit consistency, and LOI handling. These controls improve comparability between batches and reduce interpretation drift across teams and reports.

Recommended Reporting Practice

For professional summaries, report the WIP value with normalized oxide inputs, normalization basis, and a short interpretation statement. Include sample identifiers, analyst details, and notes about correction assumptions, especially for CaO*. When projects rely on threshold based decisions, pair WIP with complementary indicators and site specific ranges. This calculator supports that approach through calculation terms, exportable outputs, and an example table that encourages standardized geochemical review across routine programs.

1) What does a higher WIP value mean?
A higher WIP usually indicates fresher, less weathered silicate material because mobile cations are still relatively preserved in the analyzed sample.

2) Why is CaO* used instead of total CaO?
CaO* represents silicate calcium only. Using total CaO can overstate WIP when carbonates are present and can weaken interpretation reliability.

3) Should I normalize oxide data before comparing samples?
Yes. Normalization improves comparability when totals differ because of moisture, LOI, analytical rounding, or mixed reporting conventions across batches.

4) Can I compare WIP across different rock types?
Use caution. WIP is strongest for trend comparisons within similar lithologies because starting chemistry differs across rock types.

5) Is LOI required in this calculator?
LOI is optional. It mainly affects normalization if you choose wet basis and want totals adjusted consistently.

6) How should WIP be reported in lab summaries?
Report WIP with normalized oxides, basis used, CaO* method, sample ID, and a brief interpretation note for traceability.