[pla.gio.clase] n [Gk plagios oblique + klasis breaking, fr. klan to break--more at clast] (ca. 1868): a triclinic feldspar; esp: one having calcium or sodium in its composition
PLAGIOCLASE
Meaning of PLAGIOCLASE in English
Merriam-Webster English vocab. Английский словарь Merriam Webster. 2012