“My dear sir, you will excuse my saying that you arrive very rapidly at your conclusions.  In the first place, how can you make sure that it is a diamond?”

The man behind the counter smiled.

“I should be very ill-fitted for the position which I hold if I could not tell a diamond directly I get a sight of it, especially such a stone as this.”

“But have you no tests you can apply?”

“We have tests which we apply in cases in which doubt exists, but in this case there is no doubt whatever.  I am as sure that this is a diamond as I am sure that it is air I breathe.  However, here is a test.”

There was a wheel close by the speaker.  It was worked by a treadle.  It was more like a superior sort of traveling-tinker’s grindstone than anything else.  The man behind the counter put his foot upon the treadle.  The wheel began to revolve.  He brought the crystal into contact with the swiftly revolving wheel.  There was a s—­s—­sh!  And, in an instant, his hand was empty; the crystal had vanished into air.

“Good heavens!” he gasped.  I never saw such a look of amazement on a human countenance before.  “It’s splintered!”

POSTSCRIPT

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, and weeks, and possibly months, to the construction of that puzzle.  He had placed the diamond inside, and he had enjoyed, in anticipation and in imagination, the Alnaschar visions of the lucky finder.

Pugh blamed me for the catastrophe.  He said, and still says, that if I had not, in a measure, and quite gratuitously, insisted on a test, the man behind the counter would have been satisfied with the evidence of his organs of vision, and we should have been richer by ten thousand pounds.  But I satisfy my conscience with the reflection that what I did at any rate was honest, though, at the same time, I am perfectly well aware that such a reflection gives Pugh no sort of satisfaction.

The Great Valdez Sapphire

I know more about it than anyone else in the world, its present owner not excepted.  I can give its whole history, from the Cingalese who found it, the Spanish adventurer who stole it, the cardinal who bought it, the Pope who graciously accepted it, the favored son of the Church who received it, the gay and giddy duchess who pawned it, down to the eminent prelate who now holds it in trust as a family heirloom.