"You mean it's a fake?" said the Saint.
"Fake my eye!" said Mr. Fallon, with emphatic if inelegant expressiveness. "It's a perfectly genuine diamond, the same as any other stone you'll ever seen. The only difference is that I made it. You know how diamonds are made?"
The Saint had as good an idea of how diamonds are made as Louie Fallon was ever likely to have; but it seemed as if Louie liked talking, and in such circumstances as that Simon Templar was the last man on earth to interfere with anyone's enjoyment. He shook his head blankly.
"I thought they sort of grew," he said vaguely.
"I don't know that I should put it exactly like that," said Louie. "I'll tell you how diamonds happen. Diamonds are just carbon — like coal, or soot, or — or—"
"Paper?" suggested the Saint helpfully.
Louie frowned.
"They're carbon," he said, "which is crystallised under pressure. When the earth was all sort of hot, like you read about in your history books — before it sort of cooled down and people started to live in it and things grew on it — there was a lot of carbon. Being hot, it burnt things, and when you burn things you usually get carbon. Well, after a time, when the earth started to cool down, it sort of shrunk, like — like—"
"A shirt when it goes to the wash?" said the Saint.
"Anyway, it shrunk," said Louie, yielding the point and passing on. "And what happened then?"