igneous

Graphic Granite

Pegmatitic Granite (Quartz and Microcline KAlSi3O8)

Hardness: 6-7 Mohs; Color: White/clear quartz and salmon-pink/cream feldspar; Luster: Vitreous to pearly; Crystal structure: Trigonal/Monoclinic intergrowth; Specific gravity: 2.5-2.7.

Hardness: 6-7 Mohs
Color: White/clear quartz and salmon-pink/cream feldspar
Luster: Vitreous to pearly

Identified March 4, 2026More igneous →

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Physical properties

Hardness: 6-7 Mohs; Color: White/clear quartz and salmon-pink/cream feldspar; Luster: Vitreous to pearly; Crystal structure: Trigonal/Monoclinic intergrowth; Specific gravity: 2.5-2.7.

Formation & geological history

Formed in the late stages of magma cooling within pegmatite veins, where simultaneous crystallization of quartz and feldspar creates a runic intergrowth pattern.

Uses & applications

Used in jewelry as cabochons, interior architecture (countertops), and as decorative stones for landscaping and specimen collecting.

Geological facts

The name comes from the Greek word 'grapho' meaning 'to write,' because the intergrowth resembles ancient runic or cuneiform script.

Field identification & locations

Identified by the distinct 'runic' texture of dark/clear quartz 'characters' embedded in a feldspar matrix. Commonly found in pegmatite fields in South Dakota, Brazil, and Scandinavia.

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Blue Apatite

Fluorapatite (Ca5(PO4)3F)

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Dark Igneous Rock (Likely Basalt or Diabase)

Basalt (extrusive igneous rock) or Diabase (intrusive igneous rock - also known as Dolerite), largely composed of plagioclase feldspar, pyroxene (augite), and sometimes olivine and amphibole. Exact mineralogy would require thin section analysis.

Igneous

Magnetite

Iron(II,III) oxide (Fe3O4)

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Sodalite

Sodalite - Na8(Al6Si6O24)Cl2

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Blue Apatite

Apatite (Group), Ca5(PO4)3(F,Cl,OH)

mineral

Magnetite

Magnetite (Fe3O4)

mineral