Formula: KAlSi₃O₈

Species:  Silicates – (Tectosilicates)

 Crystal System: Monoclinic

 Name: Named in 1780 by Ermenegildo Pini for the type locality, the Adula Massif (part of the Gotthard massif), Switzerland.

A variety of K Feldspar
A more ordered low-temperature variety of Orthoclase or partially disordered Microcline.