mpact Diamonds in an Extravagant Metal Piece Found in Paraguay: Published Raman Spectra revisited

Abstract

Raman spectroscopy analysis was performed on a 303 kg pitcher-shaped metal piece, likely bearing lonsdaleite diamonds. The Raman spectra revealed four main bands: a shifted D-band (1294-1330 cm-1), a G-band (1583-1588 cm-1), an iron meteorite band (217, 284, and 402 cm-1), and a weak fourth band (1428-1460 cm-1). FWHM values (39-162 cm-1) were high, indicative of a significant lonsdaleite component (10-100%). The shifted D-peak wavenumber and FWHM values suggest the formation of lonsdaleite diamonds under high-pressure, high-temperature conditions (1068-1541 °C), possibly due to a hypervelocity collision in space. This finding strengthens the evidence for diamonds in iron meteorites and could represent the largest diamond-bearing iron meteorite recorded to date.