From German name for amber: Bernstein, literally: a stone that burns;
to Polish name for amber: Bursztyn [Other Polish names of this fossil resin are: jantar, amber];
to a surname Bursztynowicz, very likely given to a Jew from North-Eastern part of former Polish-Lithuanian Commonwealth, such as today's Lithuania or Belarus. Alternative surname Bursztyński would be given to someone from Poland proper.
Generally the suffix "-ow" suggests Russia, "-icz", "-owicz" - Lithuania or Belarus, "-ski", "-cki" - Poland. There are many Bursztyński and Bursztynowicz people in modern Poland - some of them are well known and some even have their own entries in Polish Wikipedia.