Where most have pine needle, the kauri have broad, thick leaves similar to those of the acacia. Pine cones give them away as true conifers. Massive globs of gum resin ooze from open wounds in the outer bark and fall to the ground, entombing ground dwelling plants and organisms. Buried deposits of fossil gum have been found where these forests once stood. Gum deposits in the past would be mined and used in commercial production of varnishes.
Most varnish now comes from synthetic resins.
Copal is mined in small pieces or very large chunks weighing over 100 pounds. Like amber, the Hymenaea tree is also a major source. Pieces are found containing twigs, leaves, small branches, forest floor plants like ferns and mosses as well as many kinds of 4 to 8 legged creatures. After seeing the physical similarities, it is easy to see how the untrained eye could be fooled and not recognize the difference between amber with inclusions and copal with inclusions. A rip-off artist can easily create forgeries with copal and pass them off as true amber.