Unique trace element geochemistry of pyrometamorphic apatite-supergroup minerals: a case study of fluorellestadite from burnt coal (Poland) and shale (France) post-mining waste heaps, with emphasis on boron, germanium, aluminium and titanium

Apatite-type structure is known for its flexibility towards accommodating numerous ions of different crystallographic affinities. Two samples fluorellestadite from two pyrometamorphic rocks (slags) burned waste heaps (BWH) France (LdS) and Poland (RDT) were studied in terms their trace element composition using Laser Ablation Inductively Coupled Plasma Mass Spectrometry. Boron shows an evident, persistent enrichment both the samples, with average/maximum levels 497/1040 49/106 ppm, respectively. So true magnesium (884/16766 404/6251 i.e., respectively) sodium (512/697 249/370 respectively). Germanium clearly enriched first sample (29/40 ppm) and, to a lesser degree, second one (34 ppm on average). The LdS also Al (888/1238 ppm), K (385/697 Ti (515/943 V (172/347 Cu (16/1369 ppm). RDT rich As (105/120 Sr (1072/6592 An interesting feature concerns REE pattern: Nd dominant group, respective Nd/ΣLREE Nd/(Ce+La) values 0.43 0.90; 0.37 0.66. In order highest lower average concentrations, aluminium, magnesium, titanium, boron, potassium, germanium may be essential substituents BWH apatites.