Genuine tree resin, but thousands to a few million years old rather than tens of millions.
The Baltic coast, the Dominican Republic, Myanmar, Mexico3 references
Copal is resin that has not finished becoming amber. Chemically it is on the same path — the same tree resins, the same polymerisation — but where Baltic amber is roughly forty million years old, most commercial copal is measured in thousands to a few million. It has therefore not fully lost its volatile components or completed cross-linking, and it stays softer, tackier and more reactive.
That incompleteness is the test. A drop of acetone, ether or even strong alcohol on an inconspicuous spot will soften, cloud or tackify copal within a minute or two, because the solvent can still get into the polymer. True amber is inert to the same treatment. This is the standard separation and it is reliable.
Copal is also the material behind most manufactured insect inclusions, for the simple reason that it is soft enough to work with and young enough that its own inclusions are modern species anyway. A large, pristine, textbook-perfect insect in a golden nodule sold at a market in Central America or online from Madagascar is overwhelmingly likely to be copal, and quite possibly copal with something added.
Colombian copal · Madagascan copal · East African copal
Establish which of these you are holding before judging it. A genuine piece read against another reference's rules will look wrong when it is not.
These apply to this model and not to the rest of Amber. Work them alongside the maker's general checks, not instead of them.
Copal softens, clouds or becomes tacky within a minute or two, because its polymerisation is incomplete and solvent can penetrate. Fully mature amber is unaffected. Wipe and inspect under a loupe; a dulled, slightly sticky patch is a positive result.
Baltic amber fluoresces a clear pale blue under longwave UV. Copal fluoresces feebly, generally a dull whitish. It is a fast cross-check once you have a UV torch.
Copal is the usual host for manufactured inclusions. A whole, undistorted, easily identified modern insect with no surrounding debris and no stress fractures is a made object rather than a fossil.
A small fraction of true amber. Honest as copal; a significant fraud when sold as amber, especially with insects.
An orientation for honest, unrestored condition — never an appraisal, and never a quotation.
Lovenhall StoneThe tests tell you what it is. The instrument reads a photograph and offers a name to start from — then hands you back to the tile and the coin, which are what settle it.