THE precious metals industry is big business. The clue is in the name: “precious”. So with all manner of multinational companies out to find the world’s natural treasures, Dallas Campbell and Ellie Harrison may have their work cut out tracking down some of their own but they are no strangers to a challenge, having presented numerous science and wildlife-based programmes between them.

In this new two-parter, science and nature combine as the pair travel the world in search of truly spectacular hauls, whether gems, minerals and metals, or the lucrative by-products of marine wildlife.

Pearls we all know about, and indeed Dallas goes free-diving down under in search of some particularly fine specimens.

But there is also the small matter of ambergris, a pungent substance which begins to take form in a sperm whale’s stomach, and can prove to be lucrative find, thanks to its use as an ingredient in perfume.