Heavy Mineral Identification and Quantification Using Fourier Transform Infrared Spectroscopy.

Area of Science:

• Geochemistry
• Mineralogy
• Spectroscopy

Background:

• Accurate quantification of heavy minerals (HM) is crucial for sediment analysis.
• Traditional methods like optical microscopy and scanning electron microscopy can be time-consuming and costly.

Purpose of the Study:

• To evaluate Fourier transform infrared (FT-IR) microspectroscopy in reflectance mode as a semi-automated tool for quantifying HM.
• To assess the accuracy and limitations of FT-IR microspectroscopy for HM analysis in sediments and sedimentary rocks.

Main Methods:

• Development of an in-house spectral database for common HM.
• Testing automated HM identification using FT-IR spectroscopy on synthetic mixtures.
• Evaluation of sample preparation techniques to minimize HM fractionation.

Main Results:

• FT-IR microspectroscopy accurately determined proportions of most HM in synthetic mixtures.
• The method demonstrated potential for semi-automated HM quantification.
• Limitations include inability to detect certain minerals (e.g., fluorite, pyrite) and differentiate TiO2 polymorphs.

Conclusions:

• Mid-FT-IR microspectroscopy in reflectance mode is a viable tool for accurate HM proportion determination.
• This technique offers potential advantages in simplicity, speed, and cost compared to conventional methods.
• Further development may address limitations for specific mineral groups and compounds.