igneous

Porphyritic Basalt (Chinese Writing Stone/Flower Stone)

Porphyritic Basalt (primarily Plagioclase Feldspar in a Mafic groundmass)

Hardness: 6.0-6.5 (Mohs); Color: Black or dark grey matrix with white or cream inclusions; Luster: Dull to sub-vitreous; Crystal Structure: Amorphous/Fine-grained matrix with lath-like phenocrysts; Specific Gravity: 2.8–3.0.

Hardness: 6
Color: Black or dark grey matrix with white or cream inclusions
Luster: Dull to sub-vitreous

Identified March 30, 2026More igneous →

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Physical properties

Formation & geological history

Formed from slow cooling of basaltic magma underground followed by rapid cooling at the surface. This specimen appears water-worn (tumbled), suggesting an origin in a riverbed or coastal environment from the Mesozoic or Cenozoic eras.

Uses & applications

Commonly used for lapidary work (cabochons), jewelry, decorative landscaping, and as pocket stones for collectors.

Geological facts

This specific variety is often marketed as 'Chinese Writing Stone' or 'snowflake stone' because the feldspar inclusions resemble brush strokes or calligraphic characters. The white 'letters' are actually plagioclase feldspar crystals that grew during the early cooling phase of the magma.

Field identification & locations

Identify by looking for white rectangular or lath-shaped crystals embedded in a dark, fine-grained rock. Common in volcanic regions such as the Pacific Northwest of the USA, British Columbia, and China. Collectors should look for high contrast between the dark matrix and white crystals.

Other igneous specimens

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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