A variety of jambiyas such as the above are offered for sale at the Oriental Arms website.
The 19th century offers a great wealth of travel books, as Europeans traveled to still-exotic foreign lands and described their impressions to their readers back home. Often these writers expound authoritatively on some aspect of the culture on the basis of a single observation, which may have been an anomaly, or which they may have misinterpreted. When reading them, we have to take what they say with a grain of salt--as we must with everything we read, now as much as then.
John Fryer Keane, in his Six Months in Meccah: An Account of the Mohammedan Pilgrimage to Meccah (1881), gives this description of the quality of the temper of the jambiya blade:
The only [weapon] worth description here is the Arab knife or jambiyah, with one of which most of our people had provided themselves. Jambiyahs are slightly different in make in different parts of Arabia, and are known by the names of the places that most affect the particular shape. The Meccah jambiyah is the broadest and most bent; the Mascat jambiyah is nearly straight, and about half as broad as the Meccan. The iron of the jambiyah is exceedingly soft, and sharpened by beating out the edge cold on a small anvil, shaped for this purpose only, the sharpening of jambiyah being a trade of itself. This gives the best edge I know for severing skin and hair, though of course when applied to anything hard it instantly disappears. With a newly-sharpened jambiyah a rolled-up sheepskin may be divided at one stroke.In the same book, Keane describes coming across a corpse in the desert with severe wounds inflicted by a jambiya:
I saw before me on the ground the body of a man quite recently killed. It was that of a Maghribi, who had probably been separated from his caravan, preceding ours four days. This hardy native of the North African desert must have supported life, after losing his way, until the night before, when he had been encountered by Bedawi [Bedouin] and slain. The corpse was chiefly interesting to me as illustrating the frightful nature of the wound which the terrible jambiyah (Bedawi knife) will inflict. There was a gunshot in the head, and the body was much mutilated with sword-cuts; but the jambiyah wound would have been judged by any one not acquainted with the weapon to have been made with a broad axe. The thorax and abdomen were laid open from just below where the left collarbone joins the breastbone down to the left groin, and all the viscera interposed were severed as with a razor. While inspecting this interesting object I kept my eye on the rocks, and changed my shot charges for ball. I have no doubt the perpetrators of the deed were on the hill, but I rejoined the caravan safely.Though Keane suggests that the steel of the jambiya was not tempered properly, another author of the period, Walter Harris, writes that well-tempered steel was highly prized. The following is from A Journey Through the Yemen and Some General Remarks Upon that Country (1893):
The greatest skill of the jewellers of Sanaa, who are rightly renowned for their workmanship, is exhibited in the dagger-sheaths, many of which are of rich silver-gilt, and even, at times, of gold. Perhaps the most lovely, however, are of plain polished silver inlaid with gold coins, principally of the Christian Byzantine emperors; others, again, of delicate filigree, which the natives line with coloured leathers or silks. But more than even the sheaths of these jambiyas, as they call their daggers, the natives value the blades. Antique ones are generally considered the best, and the people declare that the old art of hardening the steel has been lost. Be this as it may, there is no doubt that the modern blades are of no mean workmanship, and great prices, for the Yemen, are paid for good specimens. The two parts of the dagger are nearly always sold separately, and a Yemeni, having found a blade to suit him, has a sheath made according to his taste and wealth.