Among the edged weapons that were produced in Luristan three thousand years ago is a rare variety known as "iron mask sword." There are only about 90 extant examples. All of them were originally "purchased by museums and collectors in the 1920s and 1930s when graveyards in Luristan were being plundered en masse." [Khorasani (2006) paraphrasing Pigott (2004)]
From what I can tell, the remaining iron mask swords usually measure less than 50 cm (about 19 ˝"), which is, technically, the measurement that serves as the division between the classification of a dirk and a sword. However, for whatever reason, they are nonetheless popularly referred to as swords rather than dirks in the references.
Iron mask swords from various museums:

From the Maboubian Family Collection:

From a private Portuguese collection:

On his webpage called "The Enigma of the Luristan Iron Swords" Helmut Föll discusses this variety of Luristani weapon, writing "They are unlike any other sword ever found and have no obvious relation to older (Luristani) bronze swords (of which there are thousands)."
https://www.tf.uni-kiel.de/matwis/a.../rb_1_3.htmlMost of the authors specializing in ancient Iranian weaponry date iron mask swords to the early first millennium BC. Oscar White Muscarella (
Bronze and Iron: Ancient Near Eastern Artifacts in the Metropolitan Museum of Art) speculates that "The homogeneity of all the swords of this class suggests that they must have been made within a relatively short period of time and by a limited number of craftsmen." It's conceivable they were manufactured by a single workshop. Muscarella goes on to discuss the complexity of their manufacture: "Technologically, swords of this class represent a remarkable accomplishment of the ancient craftsman for they are one of the most complex weapon types known from antiquity...On macroscopic examination alone one has the impression that they were made in one piece, the intent, no doubt, of the craftsmen. However, both X-ray and careful laboratory examination of many examples have demonstrated that all the swords were in fact constructed from a number of units, varying in quantity from sword to sword."
A cross-sectional image of the grip of an iron mask sword, showing its various components:

They all have disc-shaped pommels that are decorated with human heads (protomes) - that hang over the edge of the disc and that seem to morph into frogs(?) on top of the pommel, grips with two molded cords, ending in guards adorned with couchant predators (lions?), and blades curiously set at a 90-degree angle to the handle. The blade and handle were made of different iron parts, cast and forged together.
It seems likely that these swords were created for some ceremonial purpose. Certainly, their unique form must have had some special significance. But their exact intent and the meaning of their iconography are lost to time.
Details of an iron mask sword from the Metropolitan Museum of Art:

I have been well aware of this strange variety of ancient Iranian sword for several years. But that awareness was exclusively the result of research. A number of examples from the collections of major museums are well documented in reference books and websites. But, until just recently, I had not spotted any on the market. I was thus amazed to see one in an auction recently and, despite its very poor condition, I submitted what turned out to be a winning bid. The sword now resides in my weapons collection and, despite its many obvious flaws, it's a standout piece. My new pickup measures 17 ˝", although it has probably lost some length to the severe corrosion. I haven't weighed it, but it is quite heavy.
In my example, one of the two heads adorning the pommel seems more animal than human. In my pic below, the head I present in the details at left is clearly human. But the details at right (of the other head) sure don't look very human. The crouching animals on either side of the guard are very hard to decipher on mine, as well. Their rear legs are visible. But one's imagination may be needed to make out much more than that. They are facing inward in the details at the bottom.

Enlargement of one of the details of a crouching animal (lion?):

The purchase actually creates a bit of dilemma for me with regard to my stated focus. For several years I have been collecting, as the title of my Forum gallery refers to it, "Bronze Weaponry from Western Asia." Even though the material I collect is, usually, from the Early
Iron Age I and II (1200 - 800 BC), most of the weapons from Iran and environs from that period were made of bronze. Thus, my collection has had an iron deficiency.
With this infusion of iron, I will now have to expand my collecting focus. I'll also have to adjust the name of my gallery at Forum - to the more inclusive "Weaponry of Western Asia." When I upload an image of the new acquisition - which will, hopefully, be within the next few days - I'll also rename the gallery.