Chondrodite
Chondrodite is a nesosilicate mineral with formula
₅
₂
₂. Although it is a fairly rare mineral, it is the most frequently encountered member of the humite group of minerals. It is formed in hydrothermal deposits from locally metamorphosed... Wikipedia
Optical properties: Biaxial(+)
Birefringence: 0.027 – 0.032
Crystal class: Prismatic (2/m); (same H-M symbol)
Crystal habit: Typically anhedral masses or grains, or as plates flattened on,, or.
Crystal system: Monoclinic
Formula mass: 351.6 g/mol
Formula (repeating unit): Mg; 5(SiO; 4); 2F; 2