Originally Posted by
earlofsodbury
Not my area of expertise, but adjacent.
First, it's worth discovering if it is actually amber - now, it almost certainly is, because when amber is faked it is usually faked to resemble valuable, clear, uniform amber - frequently (since 'Jurassic Park' - seriously!) with insect inclusions. The easiest test is a red hot needle inserted where the sun don't shine (in the amber) - i.e. where the mark won't be visible: sniff the smoke - if it smells like plastic: bin it. If it smells resinous/very slightly coniferous, the news is good. Gambling on pics alone, I'd say it looks mostly real.
There's LOTS of amber deposits worldwide - it even shows-up in the UK in a few spots, but the most prolific sources are Baltic, Myanmar and Mexico, followed by Dominican and Ukraine.
Baltic started-out being commonest - it could be picked-up on the Baltic seashore in a fair number of locations, eroding from low cliffs or below wave level. Being slightly buoyant, it could float from there to distant shores - even the UK.
For a long time Myanmar, Mexico and Dominican vastly overtook it - it was mined, and of high quality; but then Russia started to dig up vast areas of Kaliningrad, and now Baltic is #1 again.
Where you bought it might be a clue - if it's quite old and sourced in Europe, Baltic is likeliest; Asian hols: Myanmar; Americas: Mexican or Dominican. But really, there's a host of possibilities.
My guess is it's likeliest to be Baltic and quite recently dug. The murky yellow stuff didn't used to command the same value as clear and golden, but fashions change, so who knows (not me). Yours has been mounted to appear to include clear-ish parts. It could be natural - they are murky - but it rings alarm bells. You don't see that admixture often at-all, and when you do it's not very clearly delineated, so my suspicion is it's a chimaera. The clear parts may even be plastic bonded to real, low-grade amber and then mounted to hide the joins. All depends how busy you want to get with hot needles...
Even if it's real, it's not a high-grade piece, it lacks structural uniformity - the mount hides open pockets and irregularities that hurt desirability among collectors. (Or used-to, I'm out of date in every possible sense...)
If it's Baltic, it's somewhere between 38 and 55 million years old: Eocene epoch, a time not too long after the non-avian dinosaurs became extinct, but well before the human lineage fell out of the trees.
The resin comes from an ancient, almost entirely extinct group of conifers called 'umbrella pines', of which just one species clings-on in Japan.
The only real technical expert in the UK is a chap called Andy Ross who last I heard was at the National Museum of Scotland; if you're ever in Embruh, look him up and he should be able to pin it all down for you.
Not a clue as to value. Look for something similar on ebay. Doubt it'll need insuring separately. Sorry.