Reading my Viollet-le-Duc Encyclopédie Médiévale (arms and armors part, of course), I found this picture of a sort of short spear head dating from the 15th century. Looking at the weapon, we can guess than this was designed for thrusting, so couldn't help but draw a parallel with the spear part in the Fiore de'i Liberi Flower of Battle. Such a spear could be pretty efficient against a fully plate-armored opponent.

Here is the picture!

I found various appellations for such a weapon: in Viollet-le-Duc's Encyclopédie it is called a darde, but I found also some other terms like demylance (half-lance) or archegaie or derivatives (arzegaye, arcegaye aso.), that certainely originally came from assegai.

So I plan to order, in the future, such a spear head... but looking at the cross-section of the head, it looks wider than thick. I would like to see a face picture of this, to complete the stuff.

Does someone know what and where could be the actual weapon that was used here by Viollet-le-Duc? Or maybe some similar examples?

It looks like a lance head, or boarding pike head, or possibly a pike head. Not many repro lance heads out there, and it looks like most of them are hollow triangular in cross-section. It isn't a common style of repro. Maybe pike heads would be the easiest to find? Maybe even javelin heads.

(The modern "assegai" probably comes from "arzegaye" or similar, which in turn come from Arabic.)

"Azagaya" is the Spanish name of throwing spears ;) . Many more names were used, "dardo" if it had feathers, "javalina", " azcona"... And it's hard today to know the differences between them.

I don't recall ever seeing any point like that, but spears with "diamond" tips appear in inventories and documents of the XVth century.

Thanks both of you for your answers. :)
Yes, the term "arzegaie" probably came from spanish, that came from arabic, that came from berber. The long words history!

According to the Fiore treatises, I will try to use that design to draw a sort of short lance (about 6/6,5 feet long, or one toise de l'écritoire), highly specialized in thrusting for armored fight. I'll probably use the same general design, adding some longer langets. But I would be more comfortable if someone did see somewhere a sort of historical similar weapon!