New minerals in type A inclusions from Allende and clues to processes in the early solar system: Paqueite, Ca ₃ TiSi ₂ (Al,Ti,Si) ₃ O ₁₄ , and burnettite, CaVAlSiO ₆

Paqueite (Ca3TiSi2[Al,Ti,Si]3O14; IMA 2013-053) and burnettite (CaVAlSiO6; 2013-054) are new refractory minerals, occurring as euhedral to subhedral crystals within aluminous melilite in A-WP1, a type A Ca-Al-rich inclusion, CGft-12, compact (CTA) from the Allende CV3 carbonaceous chondrite. Type paqueite A-WP1 has an empirical formula of (Ca2.91Na0.11)Ti4+Si2(Al1.64Ti4+0.90Si0.24V3+0.12Sc0.07Mg0.03)O14, with trigonal structure space group P321 cell parameters = 7.943 Å, c 4.930 V 269.37 Å3, Z 1. Paqueite’s general is Ca3TiSi2(Al,Ti,Si)3O14 endmember Ca3TiSi2(Al2Ti)O14. CGft-12 Ca1.01(V3+0.56Al0.25Mg0.18)(Si1.19Al0.81)O6. It assumes diopside-type C2/c 9.80 b 8.85 5.36 ? 105.6°, 447.7 4. Burnettite’s Ca(V,Al,Mg)AlSiO6 CaVAlSiO6. likely originated condensates, but observed grains may have crystallized local V-rich melts produced during later thermal event. For compositions paqueite, clinopyroxene, perovskite suggest that As drew two distinct populations grains. Hibonite multiple populations, these were well mixed not equilibrated prior incorporation into host melilite.