perthitic


Also found in: Dictionary, Wikipedia.
Related to perthitic: Poikilitic

perthitic

[pər′thid·ik]
(geology)
Of a texture produced by perthite, exhibiting sodium feldspar as small strings, blebs, films, or irregular veinlets in a host of potassium feldspar.
References in periodicals archive ?
The patch- and vein-type perthitic inclusions in microclinic feldspar have the same composition.
Primary phases in the leucogranite are dominantly perthitic K-feldspar, quartz, and plagioclase, and in the syenogranite, K-feldspar, quartz, and plagioclase.
They are composed of euhedral to subhedral, coarsely perthitic alkali feldspar and varying amounts of interstitial quartz (Fig.
In thin section, large perthitic K-feldspar megacrysts are in a hypidiomorphic granular matrix of normal to oscillatory zoned oligoclase, perthitic orthoclase-microcline, quartz, dark brown to orange-brown biotite, pinitized cordierite, and minor muscovite.
Major minerals are quartz, plagioclase (albite-oligoclase), and perthitic microcline.
5 cm) with megacrystic to senate texture composed of perthitic K-feldspar, zoned plagioclase, quartz, and biotite (10-17%).
Dissolution of perthitic K-feldspar at near-maximum burial depths generated most of the secondary porosity.