It was a diamond, although it had splintered. In that fact lay the point of the joke. The man behind the counter had not been wrong; examination of such dust as could be collected proved that fact beyond a doubt. It was declared by experts that the diamond, at some period of its history, had been subjected to intense and continuing heat. The result had been to make it as brittle as glass.

There could be no doubt that its original owner had been an expert too. He knew where he got it from, and he probably knew what it had endured. He was aware that, from a mercantile point of view, it was worthless; it could never have been cut. So, having a turn for humor of a peculiar kind, he had devoted days, a............