Another Medieval Mystery Sword?

[Helleri]

Originally Posted by Lee

Reventlov's recognition above of pommel features in common with documented English isolated finds may very well have initiated recognition of a new localized British variant of Viking Age sword.

This type appears to be characterized by:

• A hollow pommel of cast copper alloy...
• with five lobes, the central being dominant...
• that is secured by an exposed peened tang at the top of the central lobe.
• An upper guard (pommel bar) curving away from the grip...
• and an oppositely but similarly curved cross guard.

On the basis of the curved guards, this type most closely resembles Peterson's type L or Z while the dominant central lobe recalls type S.

Tomáš Vlasatý has prepared an excellent detailed analysis of this sword comparing it with similar examples and also reviewing where it stands within several classification systems.

A minor point of correction through clarification. It would not be a "copper alloy" but a "high-copper alloy". I know it's barely relevant and doesn't seem all that important but there is a difference. Which is useful to recognize.

Copper alloys are those which contain any amount of copper but for which copper is not necessarily the primary material (such as pewter or monel). These are often also called by their principle component. Such as monel being a nickle alloy. But not always. As in with the case of pewter being categorized as a copper alloy even though a true pewter is primarily tin (true pewters are basically a reverse bronze).

High-copper alloys (such as brass or bronze) contain mostly copper with some secondary and often tertiary material (especially in older specimens the tertiary material is often an undesirable impurity that is tolerated for lack of knowledge on how to eliminate it, such as arsenic, phosphorous, or sulfur).

It's a cladistic thing in the classification of alloyed metal products (i.e. All high-copper alloys are copper alloys; Not all copper alloys are high-copper alloys).

Additionally I would say that the over all red-sh patina with gray to white oxidization in the low points, that are somewhat green or green sheen in certain spots and from different angles, makes it fairly safe to call this a true bronze (if we're interested in being more specific than asserting it as a copper/high-copper alloy). While both zinc and tin may oxidize as white. Only tin also phases more into gray and sulfates as a blueish-green. Which can produce the white from some angles and slightly greenish tinge from others. As can be seen in the OP's set of images.

This indicates the alloy being majorly comprised of copper with a low percentage by weight of tin. I would also say that the second images provided of a very similar pommel have corrosion characteristics of arsenic-copper. It may still be a true bronze. But the source for the copper or in that case may have had a fair amount of arsenic contamination. Back then they wouldn't have been all that good at working such impurities out.

To be clear that doesn't mean that these can't be the same typo-logically. Just that there was a bad luck of the draw with one in smelting. But these are somewhat different alloys. Though likely made via the same process. Back then one just couldn't control as tightly as we can today even following the exact same prescription.

I mention this bit because people seem to have a tendency to think that the differences in patina between presumed same materials are down to preservation conditions. But unless we're contrasting say an ocean wreck recovery vs. a shallow dirt-dug recovery, this really is rarely the case. At least in coloration, same materials tend to corrode the same. It takes fairly drastically different conditions to get fairly drastically different patinas.