igneous
Graphic Granite
Graphic Granite (Pegmatitic Alkaline Granite)
Hardness: 6-7 on the Mohs scale; Color: Tan, pinkish-orange matrix with dark grey or smoky quartz runes; Luster: Vitreous to greasy; Crystal structure: Crystalline intergrowth of microcline/orthoclase and quartz; Cleavage: Good in two directions for feldspar, none for quartz; Specific gravity: 2.55-2.75.
- Hardness
- 6-7 on the Mohs scale
- Luster
- Vitreous to greasy
Identified More igneous →
Explore Graphic Granite in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6-7 on the Mohs scale; Color: Tan, pinkish-orange matrix with dark grey or smoky quartz runes; Luster: Vitreous to greasy; Crystal structure: Crystalline intergrowth of microcline/orthoclase and quartz; Cleavage: Good in two directions for feldspar, none for quartz; Specific gravity: 2.55-2.75.
Formation & geological history
Formed in pegmatites through the extremely slow cooling of silica-rich magma under high water-vapor pressure, allowing the simultaneous crystallization of quartz and alkali feldspar in graphic cuneiform patterns.
Uses & applications
Used as an ornamental stone, in lapidary arts for cabochons and decorative items, and as a study specimen for crystallographic intergrowths.
Geological facts
The name 'graphic granite' comes from the visual resemblance of the quartz crystals embedded in the feldspar matrix to ancient cuneiform or runic writing, often looking like ancient letters or Arabic script.
Field identification & locations
Easily identifiable in the field by its distinct cuneiform, rune-like, or triangular intergrowths of dark quartz within a lighter-colored feldspar background. Found worldwide in pegmatite-rich regions such as the Black Hills of South Dakota, Colorado, and Scandinavia.
