Key Takeaways

  • A portable spectrometer covering VIS to SWIR, like the ASD TerraSpec Halo (Malvern Panalytical), identifies minerals in the field or on core in seconds via spectral-library matching.
  • Note: as of this writing, the TerraSpec Halo itself is listed as no longer available to purchase from Malvern Panalytical. Check current availability and successor products (TerraSpec 4) before specifying it for a new program.
  • SciAps also offers a field spectrometer line worth comparing.
  • The “AI” here is the spectral-matching engine comparing your field reading against a library of thousands of reference mineral spectra. It is genuinely ML-adjacent, but vendors frame it as spectral matching rather than a general AI model.

TL;DR

With a portable spectrometer, AI mineral identification is built in: you point it at a rock face, drill core or hand sample, and onboard library matching names the alteration minerals in seconds. Your job is to sample consistently and feed those readings into a wider alteration model. Scanning platforms use the same core logic at higher throughput.

What Is a Portable Spectrometer?

A portable spectrometer measures how a rock reflects light across the visible, near-infrared and shortwave-infrared (VIS-NIR-SWIR) range. Many alteration minerals absorb light at characteristic wavelengths in the SWIR. Clays, micas, chlorite and carbonates all leave distinctive absorption features. As a result, a reflectance spectrum works like a fingerprint for the minerals present.

Alteration mineralogy is one of the most information-dense things a geologist can read off a rock. Portable spectrometers make that reading fast and repeatable instead of purely visual and subjective. The classic instrument is the ASD TerraSpec line from Malvern Panalytical. It is a full-range (350 to 2500 nm) spectrometer that returns a mineral identification with a single trigger pull. It matches against a library of over 4,500 reference spectra and is rugged enough for both field exploration and core-shed logging.

How Do I Automate Mineral ID With a Portable Spectrometer?

The workflow runs from choosing the instrument, to letting the onboard matching work, to feeding results into a model.

Choose a current portable spectrometer

Worth flagging directly: search results indicate the TerraSpec Halo specifically is listed as no longer available for purchase. If you’re specifying new equipment, check Malvern Panalytical’s current TerraSpec 4 or successor offering. Alternatively, compare it against SciAps’s field spectrometer line rather than assuming the Halo is still orderable.

Let spectral matching identify the minerals

The AI and ML angle here is real but narrower than “general AI.” The instrument’s value comes from matching your measured spectrum against a large reference library. It identifies specific alteration minerals (kaolinite, illite, chlorite and so on) and their relative abundance. That is a classification problem the instrument solves onboard, in real time, without you running anything yourself.

However, the output is only as good as the sampling. Clean, dry surfaces and a consistent measurement spacing down the hole give far more useful data than ad hoc readings.

Feed portable spectrometer data into alteration models

Single readings answer “what is this sample?” The bigger payoff comes from many readings in 3D. Therefore, log every reading with hole ID, depth and coordinates. Those point data can then feed alteration proxy models that map alteration halos around a deposit.

Point Readings Versus Scanning

A portable spectrometer takes point measurements. That makes it cheap, flexible and ideal for field mapping or spot checks in the core shed. On the other hand, it samples only a small spot at a time.

When you need continuous coverage of every metre of core, hyperspectral point or scan systems and full core scanning platforms apply the same spectral logic at much higher throughput.

SWIR spectra also miss some minerals, such as quartz and many sulfides, so XRD analysis remains the check for full mineral quantities.

That’s why this is marked “Emerging” rather than a fully mature standalone AI product. The hardware and spectral matching are mature. Tighter integration with broader ML-based alteration modelling, such as feeding spectral results directly into 3D alteration halo models, is where the field is still moving.

FAQs

What minerals can a portable spectrometer identify?

A VIS-NIR-SWIR portable spectrometer is strongest on hydrous and carbonate minerals. That includes clays like kaolinite and illite, white micas, chlorite, epidote and carbonates. It is weaker on minerals without distinct SWIR features, such as quartz and many sulfides.

Is the TerraSpec Halo still available?

As of this writing, Malvern Panalytical lists the TerraSpec Halo as no longer available to purchase. Check the current TerraSpec range or compare field spectrometers from SciAps before buying.

Does a portable spectrometer use AI?

It uses spectral-library matching, which is a classification method closely related to machine learning. Vendors frame it as spectral matching rather than general AI. The newer AI work sits downstream, in modelling many readings together.

How is a portable spectrometer different from hyperspectral core scanning?

A portable spectrometer takes one point reading at a time. Core scanning systems image or measure whole trays continuously. Both rely on the same spectral physics, but scanning trades cost and flexibility for coverage.

Try It With Geocluster

Turning point-by-point spectral mineral IDs into a coherent 3D alteration model of your deposit is a data-integration problem. It is well suited to Geocluster, which is worth a look if you’re trying to scale spectral logging beyond single readings.