The Aztec word “copal” (Nahuatl: copalli) refers to all tree resins -old or young- that have been employed as amber incense over the centuries. Consequently, from this etymological point of view, it turns most ambers, also the ‘famous’ Baltic or the almost equal old Dominican amber, into Copal, because they are used for incense even today. LOL.
But for lack of a better word, in modern times “Copal” is used to refer to semi-fossilized amber resins or sub-fossil amber. Basically, “copal” is “young amber” and amber” is “old copal”. To say copal is “amber imitation” is pure nonsense, as it is just tree resin of younger age, which has not yet undergone some mythical transformation that is never described.
Where is the age limit? There is much theory and commercial interest. Some set the limit at 20 million years, others earlier. But, regardless of age, once the material has hardened – according to many scientists, there is no important scientific distinction to be made.
Fact is, we have no dates or specific geological information on Colombian copal or Colombian amber. Because of it’s color and hardness, some scientists believe it may be Pliocene or Pleistocene, probably about 2 to 3 million years old, in some regions even up to 16 million years old, but in others much, much younger (Santander) and may only count with some thousands, or some hundreds of years.
But opinions, theories and scientific researches and their methods vary. For example, Terrance M. Allen (Entomologist, Paleontologist) writes: “I believe, based on the fact that stellate oak (floral) hair (Family: Faqaceae, Genua: Quercus sp.) was discovered in Colombian copal/amber by this author (T.M. Allen, April 2010), and that stellate oak hair is used as an indicator fossil species found in Dominican Amber, Chiapas (Mexico) Amber, and Baltic Amber scientifically aged to be 20 million, 25 million, and 40 million years old respectively, that some Colombian copal / amber can be dated to be approximately 20 million years of age and can be termed to be true fossilized “Colombian Amber”.