title: Hexagonite
text: # Hexagonite
  
  Hexagonite is the red to pink, lilac to purple manganoan variety of tremolite. A rare amphibole, it can be transparent, translucent, and rarely opaque.
  
  ## Properties
  
  Hexagonite is pleochroic, potentially displaying varying shades of blue, violet, purple, or red. It is also known as "mangan-tremolite", since the manganese imparts the mineral's unique colors. Pink, lilac, and purple are the most common colors. Hexagonite has been successfully faceted.
  
  ## Chemical formulae and history
  
  Tremolite was discovered in 1789. Hexagonite, a varietal form of tremolite, has a Mohs hardness of 5.0-6.0. Like tremolite, it is a calcium magnesium silicate hydroxide with the formula: $Ca_2Mg_5$ $(Si_8O_{22})$ $(OH)_2.$
  
  The mineral was given the name, hexagonite, because its crystal structure was believed at one time to be hexagonal. Since then, however, it has been found to be monoclinic.
  
  ## Occurrence
  
  The mineral is found primarily in the Balmat-Edwards zinc district of Edwards, St. Lawrence County, New York, United States. It was also found in the Czech Republic in the Chýnov caves.
  
  