Yordanka Hristova Mincheva - Stefanova (Bulgarian: ÃÂþÃÂôðýúð ÃÂ¥ÃÂøÃÂÃÂþòð ÃÂøýÃÂõòð - áÃÂõÃÂðýþòð) (29 August 1923 â 28 April 2007), Aka Jordanka Mincheva - Stefanova, Jordanka MinÃÂeva - Stefanova, was a Bulgarian geologist, mineralogist and crystallographer. Her scientific interests were in sulphide mineralogy, crystal chemistry and genesis of minerals - sulphides, carbonates, arsenates, silicates etc.