title: Caldasite
text: # Caldasite
  
  Caldasite (Portuguese: Caldasito, German: Zirkonglaskopf, Spanish: Caldasita) is a rare uraniferous ore of zirconium found in the Poços de Caldas massif, located in the states of Minas Gerais and São Paulo, Brazil.
  
  It is most often found as a dark gray, very dense, hard rock. It also appears as a friable brown substance.
  
  The massif is an alkaline complex, formed by a large intrusion during the mid-Cretaceous. The ore is a result of hydrothermal alteration of the nepheline-syenitic rocks; it has also been weathered out and concentrated in paleoplacer deposits.
  
  