Paragonite, also known as Natron-Glimmer, Paragonit or Paragonita, is a mineral, related to muscovite. Its empirical formula is NaAl2(Si3Al)O10(OH)2. A wide solvus separates muscovite from paragonite, such that there is little solid solution along the vector Na+K- and apparent micas of intermediate composition is most commonly a microscopic (or even sub-microscopic) intergroth of two distinct micas, one rich in K, and the other in Na.