Hectorite Identification in Lithium Deposits
Lithium is most commonly found in pegmatites, where it occurs in minerals such as spodumene, lepidolite, and petalite. However, commercially viable lithium deposits are also present in sedimentary rocks, particularly in the clay mineral hectorite.
Hectorite is a rare, soft, white clay mineral with the chemical formula Na₀.₃(Mg,Li)₃Si₄O₁₀(OH)₂, belonging to the smectite group. It contains sodium, magnesium, and lithium, but lacks aluminum—a feature that distinguishes feature that distinguishes it from similar clays. Originally discovered near Hector, California, hectorite is increasingly valuable due to its lithium content and is used in lithiu
m extraction for batteries, as well as in cosmetics, pharmaceuticals, and as an additive in industrial applications.
Hectorite can be identified in the field using the oreXplorer™, a high-resolution, high sensitivity, field-portable NIR spectrometer that covers the full UV/VIS/NIR range from 350–2500 nm. The oreXplorer is lightweight, rugged, and designed for durability and rapid data collection. With EZ-ID™ mineral identification software and its integrated spectral, geologists can quickly and accurately identify hectorite in the field. EZ-ID’s match region capabilities allow users to focus on key absorption features and differentiate between similar minerals, such as montmorillonite.
With EZ-ID mineral identification software and its integrated spectral, geologists can quickly and accurately identify hectorite in the field. EZ-ID’s match region capabilities allow users to focus on key absorption features and differentiate between similar minerals, such as montmorillonite.
Hectorite exhibits characteristic absorption features at 1400 nm and 1900 nm, like other smectite clays such as montmorillonite. It also shows more distinct features at 2300 nm and 2380 nm, with additional, less pronounced absorptions occasionally observed near 960 nm and 1100 nm (Figure 2 Using a contact probe (10mm spot size) or the more targeted mini probe (3mm), field samples can be scanned in seconds. The resulting spectra are analyzed using EZ-ID automation, facilitating real-time mineral identification and mapping without disturbing the sample. For higher resolution needs, Spectral Evolution also offers the oreXpert model.
UV-VIS-NIR Spectroscopy has proven to be a powerful tool for mineral identification, especially for distinguishing between various types of clays. The oreXplorer enables geologists to perform fast, accurate field assessments of lithium-bearing minerals both in the field and in the lab.
Figure 2: EZ-ID mineral identification software matches your samples against three libraries of more than 1100 minerals. Here you see a library sample of hectorite.
With Spectral Evolution field portable UV-Vis-NIR spectrometers and EZ-ID mineral identification software, geologists can measure and identify minerals within seconds and cover more ground than by using traditional methods. They can identify different mineral phases, create mineral alteration maps and more accurately identify mineral pathfinders for vectoring to ore deposits. Spectral Evolution’s field portable, battery-operated oreXpress™, oreXplorer™ and oreXpert™ ultra-high resolution UV-Vis-NIR spectrometers provide quick payback with faster, more accurate mineral identification in exploration for gold, silver, diamonds, iron, nickel, copper, uranium, aluminum – in the field, core shack, or in the lab.