The autonomous train, consisting of three locomotives and carrying around 28,000 tonnes of iron ore, travelled from Tom Price mine to the port of Cape Lambert
The 3.14-carat polished emerald cut diamond, known as The Argyle Alpha, is part of the line-up of 63 rare pink, red and violet diamonds in the 2018 Argyle pink diamonds tender.
Private equity still has significant opportunities to invest in mining as companies cut debt and rebuild their balance sheets even as the sector recovers, mining specialist Denham Capital said.