Strontium carbonate (SrCO3 ).  An alkaline earth flux and the main source of strontium in glazes.  Can sometimes replace Barium carbonate in glazes (75% as much strontium as there was barium, by weight), in order to decrease toxicity.  Behaves similarly to Barium, making mattes.  With Copper gives robin’s‐egg blues.  Promotes amber colors from iron.