Max instinctively grabbed the largest stone, a crystal of at least ten carats. Cut and polished to a four- or five-carat stone, it would fetch about forty thousand dollars depending on its color grade and clarity. He studied it through a jeweler’s loupe, twisting it against the light, his mouth pursed in a sour expression. He set it aside without comment and peered at another stone, and then another. He tsked a couple of times as if disappointed by what he was seeing, then pulled a pair of reading glasses from his shirt pocket. When he had them perched on his nose, he shot Abala a disappointed look over them and opened one of his notebooks, scratching in a couple of lines with a mechanical pencil.

“What are you writing?” Abala said, suddenly unsure of himself in Max’s learned presence.

“That these stones make better gravel than gems.” Max said, making his voice shrill and adding an atrocious Dutch accent. Abala almost leapt to his feet at the insult, but Max waved him down. “But on preliminary review I judge them satisfactory for our transaction.”

He pulled a flat piece of topaz from his pants pocket, its surfaces deeply scratched. “As you know,” he said in a lecturing tone, “diamond is the hardest substance on earth. Ten on the Mohs’ scale, to be exact. Quartz, which is number seven, is often used to fool the uninitiated into thinking they are getting the deal of a lifetime.”

From the same pocket he plucked an octagonal shaft of crystal. Bearing down with considerable force he raked the quartz across the flat chunk of topaz. The edge slid off without making a mark. “As you can see, topaz is harder than quartz and hence can’t be scratched. It is eight on the Mohs’ scale, in fact.” He then took one of the smaller diamonds and ran it across the topaz. With a spine-shivering squeal the edge of the gem dug a deep scratch into the blue semiprecious stone. “So what we have here is a stone harder than eight on the Mohs’ scale.”

“Diamond,” Abala said smugly.

Max sighed as if a recalcitrant student had made a gaff. He was enjoying playing at gemologist. “Or corundum, which is nine on the Mohs’ scale. The only way to be certain this is a diamond is to test its specific gravity.”

Although Abala had dealt with diamonds many times before he knew little of their properties other than their value. Without realizing it, Hanley had piqued his interest and lowered his guard. “What is specific gravity?” he asked.

“The ratio of a stone’s weight verses the volume of water it displaces. For diamond it is exactly three point five two.” Max fiddled with his scale for a moment, calibrating it with a set of brass weights carried in a velvet-lined case. Once the scale had been zeroed he set the largest stone on the pan. “Point two two five grams. Eleven and a half carats.” He opened one of the plastic graduated cylinders and dropped the stone inside, noting how much water the gem displaced in his notebook. He then tapped the numbers into the calculator. When he saw the resulting number he glared at Raif Abala.