Chalcogen, Keszler, Trigonal

• B-O-Sc-Sr
• B-Ba-Fe-O-Y
• Al-B-O-Sr-Y
• Ba-Mg-O-Si
• B-Ba-Fe-Ho-O-Sr
• structural properties
• phase transitions
• fusion
• temperature for congruent melting
• structural transitions
• chalcogen
• metalloid
• orthoborate
• alkaline