Converse of object

• call: Sunstone, sometimes called aventurine feldspar, is yellow to red.

Preposition: in

• rock: Note the large crystals of feldspar in the rocks hereabouts.

Adjective modifier

• glassy: I picked up some specimens, with much glassy feldspar, approaching in character to trachyte.

• calcic: See also cut-off grade Gabbro A coarse grained igneous rock consisting of calcic feldspar, pyroxene and commonly hornblende and/or olivine: appx.

• pink: The rock has a spotted appearance due to large circular pink feldspars with inner concentric rings.

Modifies a noun

• phenocryst: At a second contact larger feldspar phenocrysts had grown at right angles to the contact plane.

• mineral: It has a light and dark gray banded appearance and contains light quartz and feldspar minerals with smaller amounts of dark hornblende and biotite.

• microtextures: Mechanisms of formation of feldspar microtextures produced by cooling of igneous rocks.

• crystal: Porphyry - a rock consisting of feldspar crystals embedded in a compact dark red or purple ground mass.

• gneiss: The anorthosite and garnet - pyroxene - feldspar gneisses are intimately related and the complex was probably originally layered.

• porphyry: The porphyry complex has a quartz porphyry core ( exposed in Quebrada Majaz ), which intruded an earlier feldspar porphyry complex.

Noun used with modifier

• plagioclase: Labradorite is a specific mineral, a calcic member of the plagioclase feldspar group.

• alkali: In some rocks, particularly alkali granites, the entire volume of the alkali feldspar has been recrystallized.

• potassium: Minerals such as potassium feldspar can often be included in this group since the high concentration of potassium is diagnostic.

• orthoclase: At upper right is a granite with the characteristic pinkish color given by orthoclase feldspar.

• potash: Edinbane Pottery make up their own clay body, blending very plastic clays from Dorset, china clay from Cornwall and potash feldspar.