It was later revealed that the Argyle discoveries were made well before the 21 October 1979 press announcement. Field geologists had been systematically working up the Smoke Creek drainage channel, taking alluvial samples that were collected by helicopters and sent down to Perth for examination. On 28 August 1979 one of these samples made history by yielding two diamonds, triggering off a much expanded search following the water course to its source.

Were the geologists, Frank Hughes and Warren Atkinson, working up on Barramundi Gap five weeks later, aware of the advice given in Proverbs (6:6): “Go to the ant, thou sluggard, consider her ways and be wise”? Maybe not – but it really was a long dead termite that was at the heart of the discovery of the fabulous AK1 pipe, which became the largest diamond mine in the world.

Termites need mud to build their anthills and can tunnel as deep as 90m to the water table in search of moisture. In the process they bring to the surface particles of debris, which can sometimes include gold and small diamonds. This is what had happened when, on 2 October 1979, the geologists whacked their hammer into such an anthill and uncovered the diamond, which was the key to the AK1 bonanza.

My return visit to the Argyle site last year was a little longer than my first, and left me with two lasting impressions.

One was the breathtaking performance of the project over the past quarter century. Some of the significant achievements are case studies in their own rights – for example, the marketing efforts around the champagne and cognac diamonds and the story of the Argyle signature stone, the iconic pink diamond, with each year’s Pink Diamond Tender – Argyle’s top 50 stones – attracting worldwide interest. Other achievements occurred in 1996 when Argyle broke from De Beers to sell product directly to the market and during 2000 when Rio Tinto outbid De Beers to gain 100 per cent control of Argyle Diamonds.