Let's say, for no particular reason, I am a wealthy lord living somewhere in Europe (Scotland or England, if possible) between the years 800-1000, or thereabouts. I want to assemble a record of all known hand-held weapons of war (swords, hammers, and the like, not siege weapons), and all gemstones that have been uncovered and documented at this time. Given the trade routes and range of communication at this time, would I know what a diamond is? A sapphire? Katana? Scimitar? And so on. Even if their modern distinctions hadn't been invented yet. (Oh this blue stone is actually different from this blue stone, or this sword was often called the same as this but it's longer, etc.)
Probably rare to find someone knowing what a Katana was since traveling far was very dangerous before mastering star navigation. Anyone trying to find Japan by aiming randomly would probably starve somewhere on the ocean and have a hard time finding the way back home. If you aim for the end of a certain nation, your characters can buy looted weapons from the ones who died or directly from deserters. Just like the end of Soviet in modern times was like christmas for warlords wanting cheap tanks and machineguns. The Falcata would be known from the destruction of southern Rome. Not so useful against a heavy armor thou, since chopping swords wielded like axes were not meant to pierce metal like a straight sword or pike. Macedon (ancient grece) had the Kopis which looked the same as the Falcata. They had longbows (since the stone age) but not crossbows (because that came as a counter measure against knights). Arabs had hard to master but highly effective composite bows used by foot, horse or camel. The time period also included "Vikings" in Denmark and southern Sweden and Norway that could be attacking the English along the coasts. Viking from the word "vik" (meaning bay in Swedish and Norwegian) was more of an activity than something they were. They obviously didn't have bull horns on their helmets, since that is how christians depictured them as devils. They were divided into many small kingdoms and often fighting between each other. Vikings traveled a lot using their flat boats from curved wood and used to take foreigners as slaves if they had expert knowledge about how to produce something or could be sold to Muslim nations. This gave a trade route all the way to Istanbul (Constantinopel at the time). The Vikings would have silver and amber to trade with. Some Vikings had found the secret of making straight swords of high quality steel (called Ulfbert) by making a stone oven with the hole at the bottom so that hot air would gather at the top and actually melt the metal rather than lumping together weak pieces of hot metal. This sword was rare and would give something unique to the story.
It's going to be much, much easier to approach this from the other way around. It's impossible to know exactly what was known when and where, so it makes more sense to start with a specific weapon, the katana, and ask if it's likely to have made it to Scotland at the time. As for gemstones, that's even tougher. The Staffordshire hoard, which seems to have been buried before your time period, has garnets in it that came from Sri Lanka. There's no real upper limit to the distance these things can travel without being properly recorded, and then lost forever.
I may have an answer that should be more correct than wrong. It’s difficult to say, because revisionist historians constantly reevaluate how aware ancient and medieval people were of the world at large. As such, it wouldn’t be too far-fetched to assume that an educated artistocrat was aware of distant lands, or that he was not. It’s the degree that’s in question. Regarding specific items, they did find their way around, passed from trader to trader, or looted and then looted again from their new home. A rich European collector would come across swords and gems from all over the world, but he wasn’t necessarily aware of where or when they originated. To him, every item would be a unique specimen rather than one respresenting a category of items. And sometimes they actually we freak items, created for ‘ritual purposes’. It’s also worth nothing here, that following this approach, every item would be as valuable as it was perceive to be. Some items came with vivid stories that weren’t true at all.
The British Isles were at the periphery of Europe at this point in time (IX-XI century) although there has always been extensive trade between them and continental Europe. Another thing worth pointing out, this is still the period before the start of the High Middle Ages, so no fancy longswords, or other knightly equipment so often depicted in fiction. Before the Norman conquest, I think the Saxons and the Scots wielded a lot more primitive weapons, and in the case of the former, I think the ax had been particularly popular. It might have something to do with their Germanic origins. Don't trust me on this one, though. But I still suspect the spear was one of the basic weapons for this time period. As far as gems are concerned, it would depend on your social status. They would've been available to acquire for the upper classes and the royals always had diamonds and other precious stones as a part of their regalia.
The Romans made it to the British Isles, so I don't think it would be far fetched for anyone who learned to read and write Latin in a monastery to know about whatever the Romans might have recorded and left behind. Right?
Possible. However, the monks passed on the records dealing with history, theology, and maybe some geography. If somebody had the chance to enter the monastic scriptorium, he would likely stumble upon scripts describing the Roman conquest, the early Christian period and the subsequent Saxon invasion. I'm not aware of any extensive surviving Roman records on architecture, engineering, military science, etc. Or at least not in Britain, or any part of Western Europe for that matter. It would be centuries before the West discovered the ancient texts. It was achieved through contact with the Arab world, especially the Moors in Spain and the Byzantines who fled to Italy following the fall of Constantinople where the heritage of Greece and Rome was guarded for centuries.
There's actually an island off the coast of Scotland where you can find sapphires naturally, so they'd probably know what those are. And though the first Europeans to visit Japan didn't get there until the late 1500's, there was trade between Rome and China from since before the first century on the infamous "Silk Road" and China and Japan knew of each other back then, so it's possible a sword would have made it's way from Japan to China and then again to Europe, but it's doubtful it'd be anything you'd recognize as a "katana" which didn't really come into shape until around the 10th century and only really came into full form between the 13th and 15th centuries. Before then Japanese swords tended to be straighter and look a bit more like Chinese swords.
Thanks for the comments everyone! It sounds like, to accomplish what I was hoping for, I'm going to have to bump up the timeline a few hundred years. Either that, or keep it vague.
