Information from the Getty AAT
succinite (amber)
A fossil resin ranging in age from early Eocene to early Oligocene, originating in areas along the Baltic Sea and containing succinic acid (usually 3-8%). Around 40 varieties of amber are recognized, divided into two main groups: those containing succinic acid make up the succinite group and those having little or no succinic acid belong to the retinite group.