True Baltic amber is distinguished by its yield of succinic acid, for many of the other fossil resins which are often termed amber contain either none of it, or only a very small proportion; hence the name "succinite" proposed by Professor.
Succinite has a hardness between 2 and 3,.
The Baltic amber or succinite is found as irregular nodules in a marine glauconitic sand, known as "blue earth," occurring in the Lower Oligocene strata of Samland in East Prussia, where it is now systematically mined.
Whilst succinite is the common variety of European amber, the following varieties also occur: Gedanite, or "brittle amber," closely resembling succinite, but much more brittle, not quite so hard, with a lower meltingpoint and containing no succinic acid.
Allingite, a fossil resin allied to succinite, from Switzerland.