"I am having bargain diamonds. You are wishing to see?" With hepatic yellow eyes and last week's turban sagging about his skull, the man who sidled up next to me at the Calcutta post office seemed liked a Bengali version of Old Man Steptoe.

Once we were hidden from public view, he produced a small packet of gems: they twinkled in the sun, their refractions seeming to spell out "w-e-a-l-t-h" or, at least, "d-i-n-n-e-r." To my amazement he placed a diamond between two coins, set them on the ground, then smashed the lot with a brick. Surely he had just pulverised a fortune's worth of precious stone. Regardez! Each coin was perfectly indented with the shape of the diamond, but the unscathed sparkler flashed back at me all the more seductively. Proof. Sold.

A surreptitious exchange of my all-but-last fifty dollars followed. With a conspiratorial handshake the bargain was complete. We slunk away in opposite directions. Next day, soon after my arrival in Bangkok I strode into a gem merchant?s shop, confidently produced my loot and asked, "How much would you say these are worth" He squinted through his eyepiece and murmured, "About thirty dollars, not that anyone will buy them." My jaw sagged. His kept moving: "They're industrial zircon - artificial diamonds. I hope you got them for a bargain price."

Reproduced with kind permission of the author from his collections of travel tales, The Circumference of the Knowable World and Chasing Gauguin's Ghost.