GRAPHIC  GRANITE

 

Graphic granite (a.k.a. runic granite; a.k.a. runite) has an odd but distinctive type of crystalline texture.  Graphic granites are typically bimineralic (K-feldspar & quartz) and consists of interpenetrating crystals (quartz in K-feldspar), in a way that somewhat resembles ancient cuneiform writing (“graphic”).  These rocks occur in pegmatitic granite intrusions.

  

Graphic granite (~8 cm across) from the Precambrian of Russia's Kola Peninsula.

Geologic unit & age - apparently from a Paleoproterozoic granite pegmatite intrusion, Belomorian Terrane (Kola Province), Baltic Shield (Fennoscandian Shield).

Locality: Enskoye, east of Kovdor, ~257 km west of the town of Apatity in the southwestern Kola Peninsula of far-northwestern Russia.

 


 

Graphic granites (above & below) from the Precambrian of Russia’s Kola Peninsula.

Geologic unit & age - apparently from a Paleoproterozoic granite pegmatite intrusion, Belomorian Terrane (Kola Province), Baltic Shield (Fennoscandian Shield).

Locality: Enskoye, east of Kovdor, ~257 km west of the town of Apatity in the southwestern Kola Peninsula of far-northwestern Russia.

 

 


 

Graphic granite with whitish-gray K-feldspar and dark gray quartz.

Geologic unit & age: Ruggles Pegmatite, Grafton Pegmatite Field, New Hampshire Plutonic Series, Devonian

Locality: Ruggles Pegmatite Mine, near Grafton, southern Grafton County, western New Hampshire, USA.

 


 

Graphic granite (above & below) with K-feldspar & quartz.

Geologic unit & age: Eight Mile Park Pegmatite District, Mesoproterozoic, ~1.430-1.474 b.y.

Locality: 3A Road roadcut north of Royal Gorge Bridge, west of Canon City, south-central Colorado, USA.

 


 

Graphic granite with whitish-gray K-feldspar & dark-gray quartz.

Geologic unit & age: pegmatitic granite intruding schist, Paleoproterozoic, ~1.695-1.715 b.y.

Locality: Rt. 16 roadcut southeast of Custer, Black Hills, western South Dakota, USA.

 


 

Graphic granite with whitish K-feldspar & dark-gray quartz from North Carolina, USA.

 


 

Graphic granite with whitish K-feldspar & medium-gray quartz.

Geologic unit & age: Sherman Granite, Mesoproterozoic, 1.4 b.y.

Locality: Sybille Canyon, southern Laramie Mountains, southeastern Wyoming, USA.

 


 

Graphic granite (above & below) with whitish K-feldspar & dark-gray quartz from the Precambrian of Zhitomir, Ukrainian Shield, northwestern Ukraine.

 


 

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