In addition to random diffusion, big empires between Venice and Alaska, including Persia, India, China, and the Mongols in Central Asia served as cultural "repeaters". Valuable artifacts might have actually been actively promoted in trade and taken on newer and greater significance as they changed hands.

Other even more ancient artifact transmissions across long distances include the Pompeii Lakshmi (first century CE) [1], and Greco-Roman glassware found in Southeast China (third century CE) [2].

The bigger surprise is that this trade took place across the Bering Strait, a very forbidding natural obstacle. But then again, the Yupik peoples have historically spanned the Bering Strait though to central Alaska [3], so they are a probably final link for the artifact between Eurasia and North American populations.

1. https://en.wikipedia.org/wiki/Pompeii_Lakshmi

2. https://en.wikipedia.org/wiki/Serica#/media/File:Green_glass...

3. https://en.wikipedia.org/wiki/Yupik_peoples

This is a really interesting point that seems to be overlooked, but is unbelievably interesting. My understanding is that there was neighborly trading over the Bering strait and from Newfoundland to Greenland...

It makes me wonder, could a merchant sailor in a pub in England have heard a story from the a friend of a friend of a friend about the North American coast?

This transfer of beads happened during the time of the mongol empire which stretched from deep within europe to china and all the way to the eastern siberia.

It is no secret that the mongol empire was one of the greatest facilitator of cultural and economic diffusion. Generally the idea was that goods and ideas flowed from the east to the west, but certainly some from the west flowed to the east and eventually to alaska.

It would be interesting to know if anything from alaska made its way westward.

I disagree that it would be indistinguishable. You need to chain together a long series of probabilities that leads to exponentially less product arriving through diffusion than through long-range traders, and a clear trail would result.

The typical approach to direct contact is to look for the signs of the people making the journey (genetic, linguistic, and cultural transmission). If you don't have these, they're often practically indistinguishable because the archaeological record inherently tends to be spotty, without continuous data points for uncommon trade goods. Moreover, the Asian northeast is vast and only lightly surveyed.

You only need time. The probability of any individual product arriving is indeed small. The probability of some item arriving is certainty, given enough time.