'Plagioclase' definitions:
Definition of 'plagioclase'
noun
Any of a series of triclinic feldspars that form rocks [syn: plagioclase,
oligoclase]
Definition of 'Plagioclase'
- Plagioclase \Pla"gi*o*clase\, n. [Gr. pla`gios oblique + kla^n
to break.] (Min.)
A general term used of any triclinic feldspar. See the Note
under Feldspar.
[1913 Webster]