noun
definition
A coarsely crystalline igneous or plutonic rock composed primarily of feldspar and quartz, normally with muscovite and/or biotite mica.
Examples of pegmatite in a Sentence
The granite, which is intruded through the Eocene beds, is associated with a pegmatite containing tourmaline and cassiterite.
Large sheets of muscovite, such as are of commercial value, are found only in the very coarsely crystallized pegmatite veins traversing granite, gneiss or micaschist.
The feldspar of a splendid pegmatite and its products of disintegration on the borders of Owari, Mino and Mikawa form the raw material of the very extensive ceramic industry of this district, with its chief place, Seto.
Chaper found diamond with corundum in a decomposed red pegmatite vein in gneiss.
The varying texture of this rock, its irregular foliation and jointing, and its ramifying veins of pegmatite give it very unequal powers of resistance.
In pegmatite (graphic granite) and granophyre it often forms a regular intergrowth with felspar.
Pink and white pegmatite typically occurs in veins and contains coarse grained quartz and feldspar.
Eight of the holes drilled on Oleninskoye intersected pegmatite within the area where the vein intersection was anticipated.