Marco Polo alludes to the treasures brought from the Isle of Ormus, as “spices, pearls, precious stones, cloth of gold and silver, elephant’s teeth, and all other precious things from India.”  In Balaxiam he says are found “ballasses and other precious stones of great value.  No man, on pain of death, dare either dig such stones or carry them out of the country, for all those stones are the King’s.  Other mountains also in this province yield stones called lapis lazuli, whereof the best azure is made.  The like is not found in the world.  These mines also yield silver, brass, and lead.”  He speaks of the natives as wearing gold and silver earrings, “with pearls and-other stones artificially wrought in them.”  In a certain river, too, are found jasper and chalcedons.

Marco Polo’s account of how diamonds are obtained is ingenuous in its reckless defiance of fact.  He says that in the mountains “there are certain great deep valleys to the bottom of which there is no access.  Wherefore the men who go in search of the diamonds take with them pieces of meat,” which they throw into this deep valley.  He relates that the eagles, when they see these pieces of meat, fly down and get them, and when they return, they settle on the higher rocks, when the men raise a shout, and drive them off.  After the eagles have thus been driven away, “the men recover the pieces of meat, and find them full of diamonds, which have stuck to them.  For the abundance of diamonds down in the depths,” continues Marco Polo, naively “is astonishing; but nobody can get down, and if one could, it would be only to be incontinently devoured by the serpents which are so rife there.”  A further account proceeds thus:  “The diamonds are so scattered and dispersed in the earth, and lie so thin, that in the most plentiful mines it is rare to find one in digging;... they are frequently enclosed in clods,... some... have the earth so fixed about them that till they grind them on a rough stone with sand, they cannot move it sufficiently to discover they are transparent or... to know them from other stones.  At the first opening of the mine, the unskilful labourers sometimes, to try what they have found, lay them on a great stone, and, striking them one with another, to their costly experience, discover that they have broken a diamond....  They fill a cistern with water, soaking therein as much of the earth they dig out of the mine as it can hold at one time, breaking the clods, picking out the great stones, and stirring it with shovels... then they open a vent, letting out the foul water, and supply it with clean, till the earthy substance be all washed away, and only the gravelly one remains at the bottom.”  A process of sifting and drying is then described, and the gravel is all spread out to be examined, “they never examine the stuff they have washed but between the hours of ten and three, lest any cloud, by interposing, intercept the brisk beams of the sun, which they hold very necessary to assist them in their search, the diamonds constantly reflecting them when they shine on them, rendering themselves thereby the more conspicuous.”