The problem with this suggestion is that ambra, ambre, amber is (at least originally) ambergris (a whale product), like Arabic 'anbar, and that this name was only secondarily transferred to Bernstein (a product of tree resin).
That is what most linguists say. However, apparently also a Germanic etymology is possible (prefix 'an' + ber= burn, see also German Bern-stein).
It is important to know what prefix an- means, Persian angom actually means "gum".There's NP انگم/angom for amber which forms on fruit trees.
OK. I got you wrong. I thought you said, trade is not a route for loan words at all. But if the Arabic word had meant amber rather than ambergris then there would have been a reason. Amber comes mainly from the Baltic Sea shore.The reasons are usually like a lack of the (precise) concept of the traded item, and the prestige or prowess of the seller, etc.
In Bundahishn, ambar is said to be the dung of the legendary three-legged ass, it seems to be clear that medieval Persians didn't know what it is, so the original one could be amber, not ambergris.Trade itself is not a sufficient reason for assuming a borrowing. Vikings exported amber not ambergris, while Persian and Arabic 'anbar means the latter. Chronologically, the attestation the word is northward: first Arabic, then Romance, then Germanic.
The use of ambre in the sense of ambre jaune developed 13th century French. That is much too late and confined to European languages.In Bundahishn, ambar is said to be the dung of the legendary three-legged ass, it seems to be clear that medieval Persians didn't know what it is, so the original one could be amber, not ambergris.
What do you know about the name of Ambrones? It seems in the ancient time, they were famous for amber gathering.The use of ambre in the sense of ambre jaune developed 13th century French. That is much too late and confined to European languages.
Germanic languages don't use the word amber. The words they use is either from the verbal root of rub (Danish rav) or they call amber "burning stone" (Brennstein, Bernstein, bärnsten, from Low German) or in older High German from agat- (agate). Only English uses amber but that is clearly a French loan (around 1400).