Nosean

Nosean is an uncommon member of the feldspathoid group that is closely related to Lazurite and Hauyne. It can sometimes be very difficult to distinguish these three minerals without a complex chemical analysis. Nosean forms a solid solution series with Hauyne, where Hauyne contains calcium in place of some of the sodium, whereas Nosean lacks any calcium and has water in its chemical structure.

Nosean is named after German mineralogist and chemist Karl Wilhelm Nose (1753-1835).

Exceptional Nosean with an electric-blue color comes from Sar-e Sang, Kokcha Valley, Badakshan Province, Afghanistan, where it forms most often as a significant inclusion of Sodalite coating Nepheline.

Complex, prismatic colorless microcrystals of Nosean come from the In den Dellen quarries, Niedermendig, Eifel Mountains, Germany; and well-formed microcrystals from Vetralla, Vico Lake, Viterbo Province, Latium, Italy.