And nearly all of the tin used in Bronze Age tools came from a single mining area in what is now Afghanistan. Recommended: Eric Cline's "1177BC, The Year Civilization Collapsed", great read on the state of the economy of the time (and from the title, its rather spectacular collapse).
I think you mean the somewhat more limited "... used in eastern Mediterranean Bronze Age tools ..."
In the video linked to by dpeck, Cline talks about Afghanistan as a tin source at https://youtu.be/hyry8mgXiTk?t=878 . He mentions Cornwall and Turkey as two other sources, with "the vast majority" coming from Afghanistan.
Cornwall provided a lot of the tin for Europe. A clue that Cline is talking about a regional supply is that he mentioned Cyprus as the source for copper, when NW Europe had other sources, like Great Orme in Wales.
edit: BTW they also contain Europe's largest reserves of lithium (and world's cheapest to mine), if you look only at hard rock it's actually the biggest.
When were the trade lines to China established? Skimming of the Wikipedia article about the silk road suggests that its precursors are from around that time.
"They journeyed from Greater Scythia by way of the Tyrrhenian Sea and the Pillars of Hercules, and dwelt for a long course of time in Spain among the most savage tribes, but nowhere could they be subdued by any race, however barbarous.
Thence they came, twelve hundred years after the people of Israel crossed the Red Sea, to their home in the west where they still live today."
It wasn't referred to as the Black Sea, that was my summation of the journey as described in the legend. It is very similar to what arethuza posted about the mythical origin of the Scots.
I can't imagine the English name "the Black Sea" would have survived in Celtic, but it's interesting because the origins of the people and language appear to have been in Asia Minor (Galatia, modern-day Turkey).
Amber was called "the gold of the north"(1), there was even established a trade route (similar as famous Silk Route) from the North and Baltic seas to Mediterranean Sea.
It's also been known for awhile that the metal products often went the other way. As early as 1200 BC a proto-Celtic people had some major copper/iron works set up along the Danube, and the trade went down the river and over Anatolia to the mideast. Jewelry with Celtic symbols were found in Sumeria.
Even further afield, there were extensive copper and gold mines, for export, in very early Ireland, also proto-Celtic times.
Per Wikipedia re: mines in Cork and Kerry: "mining and metalworking took place there between 2400 and 1800 BC. ... Mines in Cork and Kerry are believed to have produced as much as 370 tonnes of copper during the Bronze Age. As only about 0.2% of this can be accounted for in excavated bronze artefacts, it is surmised that Ireland was a major exporter of copper during this period."
Third paragraph in the article states that Nordic amber was heavily prized in Mycenaean Greece. Distances and climate in Europe are actually quite reasonable for overland journeys, especially considering that the ancient empires of the Middle East interacted in a substantial way for several millennia despite being much farther than a Greece-Sweden transit.
