It used to be a touchy subject within the bank - and possibly still is. The word comes from adamant, which is still used as a substitute for unbreakable.

It comes into English via Latin and old French diamante. The first use in writing that I found came in 1310, when it was spelt diamaunde.

I was in the Broome museum a few years ago and I came across an interesting story from Mervyn Prime about the bank and diamonds. During wartime Captain Takeo Shibata from Japan invented long-range fuel tanks and decided to attack the airstrip at Broome to take out land-based military aircraft, which reconnaissance aircraft crew reported were on the airstrip.

But as the Zero aircraft - not bombers - arrived early in the March morning of 1942 they discovered many flying boats in Roebuck Bay and decided to attack them instead. Figures vary, but at least 50 people, mostly Dutch, were killed on the flying boats, which were being refuelled on the way from Java to Perth.

Some drowned and reports said some were attacked by sharks. Several Japanese airmen killed at this time were then promoted a rank- but I understand no Broome people were killed in the raid.

The Prime Minister, John Curtin, said rumours of a heavy loss of life by Broome people were "utterly untrue". Another raid soon after took place on the airstrip and one person on the ground - a Malay walking across the strip - was killed.

The attack leader, Zenziro Miyano, was killed in 1943 and was promoted two ranks - not a nice way to be promoted. But back to the diamonds.

At Java, Captain Ivan Smirnoff was handed a small package.

He was told the Broome airstrip was "okay for the time being", with no mention of the attack on Roebuck Bay. His plane was shot down in Carnot Bay, just north of Broome. Smirnoff was flown to Perth where an official of the Commonwealth Bank asked him for the package. Smirnoff was told the package contained diamonds valued at $600,000 - perhaps more than $40 million in today's values, but don't quote me on that.

A few days after Smirnoff's plane was shot down Jack Palmer sailed his lugger into Carnot Bay and saw the plane that had crashed. He found the package and, surprise, surprise, it contained some diamonds.

Aborigines in the area apparently threw diamonds away when told people were searching for them.

For the next few years diamonds, or the places where diamonds might have been hidden, were found.

Diamonds recovered amounted to only about $42,000. Incidentally, I said that Captain Shibata invented the long-range fuel tanks for the Zero aircraft.

He survived the war and I have a photo of him as an old man at home with his wife.

In a letter after the war he said: "I never issued my instruction as to the target to be the town. Please accept my apologies if some stray bullets fell into the town."