Patrick Gundersen's team tackles harsh terrain in the hunt for aquamarine. Plus, the Rubyvale Boys battle against mechanical malfunctions.

Newcomer, Neil Wilkinson Jr., abseils down a deadly mineshaft in search of cubic fluorite, while Jarrin and Hugh take the plunge into frigid waters.

The Rubyvale Boys help a neighbour who is in need for a cut of the sapphire spoils. Tom heads to the Tasmanian mountains in search of meteorite-impact glass.

Patrick and Kirsty revisit a 15-year-old ocean kyanite dig site. Kyle and Glenn must pivot from quartz to black agate to reach their huge dig target.

In their desperate bid to set up a second sapphire mine, The Rubyvale Boys face a cascade of equipment failures while Frankie and Ebriony trudge through dense grasslands on the hunt for peridot.

Patrick Gundersen’s delicate operation to extract Australia’s largest smoky quartz cluster is derailed by hard ground, while Jarrin and Hugh’s stichtite dig forces them to resort to more explosive measures. Kyle’s relationship with his girlfriend, Jillian, is on the rocks as the pair futilely hunt for Killiecrankie diamonds.