The majority of these bowlders have been derived from the immediate vicinity, but many consisting of a coarse pegmatite carrying considerable quantities of ilmenite were observed.
The specimen was taken from a pegmatite dike at its contact with an amphibolite.
The rock was primitive, granite and pegmatite in several varities, with a few exceptions of anagenitic formation.
I observed Pegmatite of a white colour, and hornblende Porphyry and Diorite.
Granite andpegmatite were round some lagoons near the creek from the southward.
The bed of it had again become sandy, with small pebbles of pegmatiteand quartz.
Pebbles and blocks of Pegmatite covered the bed of the creek.
A high range of Pegmatite descended from the table land far into the valley, from east to west; and an isolated peak was seen to the west of it at the left bank of the river.
Many of them were composed of quartzite and pegmatite [Graphic granite, composed of quartz and laminated felspar.
The country was very mountainous; granitic andpegmatite ranges bounded the valley on both sides.
Pegmatite and Porphyry (with a very few small crystals of felspar) and Gneiss?
Mossite is from a pegmatite vein near Moss in Norway, and tapiolite is from Finland.
The Virginia production comes from pegmatite dikes cutting through gabbros, syenites, and gneisses.
Tungsten is likewise found in original segregations in igneous rocks and in pegmatite dikes, but these deposits are of comparatively small commercial importance.
It is a rather common mineral in silicated zones in limestones near igneous contacts, but gem tourmalines are found principally in pegmatite dikes.
In North Carolina sapphire has been found in pegmatite dikes.
In general the principal gem minerals, except pearl and turquoise, occur as original constituents in igneous intrusives, usually of a pegmatite or peridotite nature.
This inorganic graphite in pegmatite veins resembles Ceylon graphite, in breaking into large lumps and chips, but supplies are very limited.
Pitchblende has been found in gold-bearing veins in Gilpin County, eastern Colorado, and in pegmatite dikes in the Appalachians, but these deposits are of no commercial importance.
The former deposits contain arsenopyrite and copper-bearing pyrite impregnating a mica-quartz-schist, adjacent to and in apparent genetic relation with aplite orpegmatite intrusives.
Emeralds have been found in pegmatite dikes in North Carolina and New England, but the production is insignificant.
Some of the graphite also occurs inpegmatite intrusives and adjacent wall rocks.
The deep-zone minerals are not unlike thepegmatite minerals in their grouping and associations.
The basic types of the former are represented by the sills of epidiorite and hornblende gneiss in Glen Muick and Glen Callater, which have been permeated by granite and pegmatite in veins and lenticles, often foliated.
Some other localities in the United States yield amazon-stone, and it is also found in pegmatite in Madagascar.
It was first discovered as slender crystals, sometimes a foot in length, in the pegmatite veins of the granite of Rundemyr, near Kongsbeig in Rorway, and was named by F.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "pegmatite" in a variety of sentences. We hope that you will now be able to make sentences using this word.
