## 3 Materials  
The spectral data used in this study are sourced from several CSIRO-led collaborations with the iron ore industry. They total seven individual spectral datasets from two different deposit types. Namely, RC chips spectrally scanned with the HyLoggerTM from the Rocklea Dome CID [1; 6; 31; 32] and a combination of RC chips, diamond core and pulps from across \begin{table}
\begin{tabular}{c c c c c} \hline \hline \begin{tabular}{c} **-** \\ **-** \\ \end{tabular} & \begin{tabular}{c} **Lower** \\ **Bound (nm)** \\ \end{tabular} & \begin{tabular}{c} **Upper** \\ **Bound (nm)** \\ \end{tabular} & \begin{tabular}{c} **Polynomial** \\ **Degree** \\ \end{tabular} & \begin{tabular}{c} **TSGTM** \\ \end{tabular} & \begin{tabular}{c} **Pfit Measure** \\ \end{tabular} & \begin{tabular}{c} **Usage** \\ \end{tabular} \\ \hline \begin{tabular}{c} Fe Oxide \\ Wavelength \\ \end{tabular} & 750 & 1300 & 10 & Wavelength at minimum & Hematite/Goethite \\ \hline \begin{tabular}{c} Fe Oxide FWHM \\ \end{tabular} & 750 & 1300 & 10 & FWHM & \begin{tabular}{c} Hematite/Vitroous \\ Goethite/Ocherous goethite \\ \end{tabular} \\ \hline \begin{tabular}{c} Fe Oxide Depth \\ \end{tabular} & 750 & 1300 & 10 & Relative Depth & Goethite presence \\ \hline \
\begin{tabular}{c} SWIR Dropoff \\ \end{tabular} & 1550 & 1850 & 10 & Relative Depth & Vitreous goethite \\ \hline
\begin{tabular}{c} Water Depth \\ \end{tabular} & 1850 & 2100 & 10 & Relative Depth & Bound/Unbound water content \\ \hline \hline \end{tabular}
\end{table} 
Table 1: The spectral metrics used in this study. The calculation of the metrics was performed in the CSIRO-developed TSGTM software. The last column “Usage” shows the general purpose of the metric. the Hamersley Basin in Western Australia. The HyLoggerTM has two spectrometers in the 380-2500 nm spectral region. The first is a silicon-detector grating spectrometer covering the 380-1072 nm spectral region and the second is an InSb-detector FTIR (Fourier Transform Infrared) spectrometer covering the 1072-2500 nm spectral region. The HyLoggerTM produces spectral samples approximately every 1 cm when used with drillcore or a total of 3 samples per chip bin averaged to a single spectrum when used with chips. The combined spectral dataset is comprised of 1 pulp dataset (BIF), 2 diamond core (BID) and 4 RC chip datasets, with the latter comprised of one CID and three BID formations (see Table 2). The Rocklea Dome dataset is publicly available; however, the remaining 6 datasets are sourced from company datasets and are subject to intellectual property constraints. In the latter case, it is not possible to identify the spectral dataset owners nor to specifically geolocate the datasets within the Hamersley Basin. All the data have been, if not originally, spectrally resampled to a 1 nm spectral sampling between 380 and 2500 nm. Drillcore is placed into core trays containing 3-4 rows, dependent on the core tray, with a length of 1 m per row. The core is first cleaned prior to scanning and then the tray is placed on the HyLoggerTM x-y translation table for scanning and surface reflectance determination. In a similar manner, RC chip samples are placed into a tray comprised of a number of individual chip buckets where each chip bucket sample is representative of the user chip metearge. The HyLoggerTM, in this case, is moved on the x-y translation table from bucket to bucket collecting 3 spectral samples per bucket and averaging those into a singular surface reflectance value. Prior to showing results, it is prudent to remind the reader of the spectral absorption wavelengths expected in the Hamersley Basin spectral datasets. Table 3 shows the mineral in question in column 1 and the corresponding absorption wavelengths in column for a given study (column 3). It is noted that hematite is noted as occurring below 890 nm and goethite above 890 nm. The kaolinite absorption feature is also shown since it is used to reduce the impact of alteration minerals that may be present in the datasets.