Well, if I knew that, the mystery might be solved. 
But, for example, maybe in conjunction with a stick - sort of like this:
If an alien ran across a button in a field, they might be hard pressed to determine it’s function without the accompanying fabric with a hole in it.
Whatever they are, I’m guessing there is another part of them that was made out of a less durable material.
The dodecahedrons are bulky for their size, with stick-outs all over their surface. Actual Roman cloak pins tend to have a either a flat section to lie against the fabric, or a clear bow shape with a pin. All the decoration faces outwards. What you’re proposing is a recipe for snags and bruises.
And why on earth would you make the pin-holder part out of the harder substance, but make the pin , the part that actually penetrates the fabric and does all the holding, out of less durable material?. Even your example has it exactly the opposite. Have you ever worn a cloak with a cloakpin? Or a kiltpin? Nice strong pins are what you want.
In any case, pin+holder-type cloak brooches, like your basic penannular brooch, work by having a space for the fabric to pass through:
Even your leather hair pin has that, Where is that in a dodecahedron?
Apologies, Lucas_Jackson, I did appreciate the joke. I thought the fact that knitting is a later invention might be interesting. And then I learned something interesting from Mr Dibble about prehistoric knitting.
I learned something today!
Except that the Roman Empire was also really good at spreading cults from one part of the Empire to other parts.
Lacking Legos and Barbie shoes, the Romans made the dodecahedrons to step on in the dark after having kids.
Some cults, like the Orphic, Mithraic and Isidian. Others were more tied to places, like the Samothracian and Eleusinian Mysteries.
The syncretic Gallo-Roman religion was a bit of both - but we find some of its cultic artefacts only in the Britain-Gaul-Germania region, like Jupiter columns or the particular form of temple used in the region.
It might be interesting to map the distribution of Jupiter columns vs dodecahedra.
I’ve studied these (tried to cast one in pewter once - it didn’t work very well). They seem to big to be used as thrown or cast game pieces. The different size of the holes seems to be very deliberate; the knobs on the vertices don’t seem to be so critical in their size or the length of their standoff.
I’ve seen theories that they were used for loom knitting to make gloves, in a single knitted piece; it does seem possible that the knobs are for wrapping or lashing cord around, but the experimental demonstration of glove knitting I saw looked extremely awkward.
My own pet hypotheses on these:
They could be used as a sort of universal retort stand, to hold a variety of different small scent or medicine bottles - small Roman bottles often had pointed or oval bottoms.
They could be an apprentice’s masterpiece - something a worker in Bronze was expected to make to demonstrate their ability to cast intricate shapes, hollow forms and precise holes.
According to the wiki they range in size from 4 to 11 centimetres, and the holes in them are of varying diameter. If that means “varying between different examples of the objects” then they can’t be a universal retort stand, nor so far as I know did the Romans use retorts of any sort (aside from “It says Romans Go Home!” “No it doesn’t!”).
If however the holes are consistent between examples of the objects, despite the varying object size, perhaps.
The claim that the dodecahedrons were not written about, seems wrong…
They are written about by the greek philosophers, and by the indians who had been learning of greek philosophy.
And… smaller examples were found in the east…
It seems that the fact that none of the dodecahedrons show any usage marks, means they were not used. They were just decoration… symbols of some philosophy. So it must be that the philosophy was recorded somewhere. and they are only found in the greek philosophers writings, that is most likely here. Where It seems they represent whollistic power…
So while seemingly they wanted to own the best dodecahedron it also represents they believe in philosophy, science over being god worshipers at the temples. Like a sign that they are strong atheists. Maybe the meaning is the metal workers guild were not going to build poor quality weapons and get them worshipped into fitness at a temple. The temples were not going to fix their weapons, their weapons were good due to … philosophy, science… atheist ideas.
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Dodecahedrons, the shape, got written about plenty: They’re one of the five Platonic Solids.
The bronze artifacts specifically, however, were not written about.
They vary between examples, and the holes in any single example are different sizes too.
But only Gallo-Germanic apprentices?
Kind of a moot point - since they’ve only been found in a limited region, your question can be asked of any explanation of what they were for, but yes, that approximate region does have a later mediaeval tradition that fits the idea.
Sure. But some phenomenon (some cults, fashion fads) are more understandable as regional phenomena, others (tools, military equipment) are not.
I think apprenticeship culture would be more the latter than the former, given the connected nature of the Roman Imperial economy. I’m not saying regions didn’t specialize in particular manufacturing or the like, but overall, bronzework wasn’t one of those, we find Roman bronze workshops as far afield as Lebanon.
Also, the particular Apprentice->Journeyman->Master structure that involved masterpieces only developed with the medieval guild, as far as I know. You’d need to provide evidence that the same sort of thing happened in other Roman crafts.
Lastly, medieval masterpieces tend to be much more actual pieces of the type a working artisan would produce, only with all the skill the artisan could muster - not some tchotchke.
Producing some standard template non-utilitarian proof item seems more a modern industrial phenomenon. Much more likely that in practical Rome, that kind of object, if made at all, would be something practical yet decorated, similar to the medieval masterpieces.
That’s not cultural continuity from Rome, though, that’s a quaint regional holdout of a phenomenon that developed in the Middle Ages and used to have wider European currency. And that’s a behaviour, not an artefact.
Your question appears to be ‘is it possible for a tradition to be limited to a geographic area’, so I think the answer is ‘yes, it is possible’.
No, that was not my question - why would I question that, when I had already provided examples in this thread of that kind of thing in the Empire, with regards to cults? I’m not questioning the possibility of regional traditions for anything. In any case, mere possibility is a red herring, I already called out Russell’s Amphora in this thread.
My question was more specific than that, with reference to the specific sub-set of Imperial artisans you were referencing. And a reference to Medieval behaviours for non-Roman-derived cultures doesn’t answer it. There’s no cultural continuity there. Some references to
a) the existence of masterpieces as a Roman artisan phenomenon at all; or
b) other region-bound Roman artisan traditions (not artistic styles)
would answer it.
I don’t think I was necessarily imagining continuity between the two traditions (one hypothetical), but it did surprise me to find the geographic overlap - and to my untrained eye, even some of the Germanic apprentice masterpieces from later periods seem to have a similar feel to them - although I have no idea how I would describe the similarity I think I am perceiving - maybe something about the ornamentation of an object that does not actually require ornamentation. Probably my imagination.
I dunno. ‘For religious purposes’ might as well just be pronounced ‘we don’t know’, in archaeology.
After extensively searching for a few minutes online I could find no solid data about the dodecahedrons. Measurements of the shape and the hole diameters would be useful information but I found not one useful specific detail. The same general information was repeated in website after website, as were the same guesses as to their purpose, and I suspect but one of them wrong.
If these were measuring devices of any kind they would have to have some kind of consistency in size among them all. If that was the case I think the data demonstrating that would be repeated in all those clone sites. That absence tells me there is no consistency yet discovered and these were not measuring tools.
If these were gambling devices then however they were manipulated they would have to produce a result with the appearance of fairness. The small number of pictures of whole dodecahedrons repeated in all the websites indicate to me there aren’t many whole examples that could be tested. If anyone had tested any of them at all to see if they would roll, bounce, spin, or whatever in something that seemed random enogh to bet one that would have been repeated as well. I think they aren’t well balanced enough to be used for gambling, and probably not sturdy enough either.
I also have to point out that from the small number of pictures available the metal dodecahedrons do not look to me like they’ve been cast in one 3D piece, rather that they’ve been welded together in some manner from multiple cast faces. Some simple destructive or more complicated non-destructive testing could determine that. If they are not cast in one piece they don’t look like work only master craftsmen could produce.
Knitting gloves? Let’s be serious here. Is there any evidence people wore fitted knit gloves in the 2nd and 4th centuries to the extent that specialized devices were invented to produce them? I think if these dodecahedrons were that utile there would have been a lot more of them turning up.
Religious significance? Cool shape made up of 12 pentagrams that fits. But with a hole in each face instead of some symbols or imagery then it’s not religious.
There is one good theory though. These are candle holders. They are the kind of candle holders they hawked in 2nd and 4th century infomercials. “Tired of trying to hold up a skinny candle in a huge holder?” is narrated over a scene of a candle falling over and setting setting a fine linen arras ablaze. “Then you need the Roman Dodecaholder! Only the Roman Dodecaholder holds candles of XII different sizes! Throw out those II and III hole candle holders! Even V, VI, or VII hole candle holders are nothing compared to the XII holes in the Roman Dodecaholder!”
The presence of wax in some of the objects proves without a doubt that they were either intended to be candle holders or they had no purpose useful enough for anyone to care about and they were eventually used as candle holders anyway.
You can find data on individual dodecahedra that go into quite a lot of detail, but you’ll need academic library access for most info.
No. The bodies are mentioned as cast as one piece, in some the knobs are also integral, in others, they’re attached on by pins.
Lots of religious items are without additional symbology - how would you tell prayer beads from worry beads, for instance?
Or … that wax and wax-containing compounds were (and is are) used in metalwork for various purposes, from casting to workholding to polishing…
ETA: There’s also no explanation for why a useful tool (a candle holder) would be restricted to only part of the Empire - did they not use candles in the rest of the Empire (they definitely did)?