FIG. 4.

Sample 4 (785 nm excitation). (A) Clear signatures of disordered carbon (1300–1600 cm⁻¹) and quartz (below 500 cm⁻¹); (B) strong disordered carbon signal with two peaks of feldspar and very weak features of hematite (below 600 cm⁻¹); (C) disordered carbon and clear hematite features below 700 cm⁻¹, note the shoulder at around 1320 cm⁻¹ representative of disordered hematite; (D) pyrite.