igneous

Basalt with Quartz/Plagioclase Inclusions

Mafic volcanic rock (Basaltic)

Hardness: 6-7 on Mohs scale; Color: dark grey to black matrix with creamy white inclusions; Luster: Dull/earthy for matrix, vitreous for inclusions; Structure: Aphanitic with phenocrysts.

Hardness: 6-7 on Mohs scale
Color: dark grey to black matrix with creamy white inclusions
Luster: Dull/earthy for matrix, vitreous for inclusions

Identified May 3, 2026More igneous →

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Physical properties

Hardness: 6-7 on Mohs scale; Color: dark grey to black matrix with creamy white inclusions; Luster: Dull/earthy for matrix, vitreous for inclusions; Structure: Aphanitic with phenocrysts.

Formation & geological history

Formed from the rapid cooling of magnesium-rich and iron-rich lava at or near the Earth's surface. The lighter inclusions suggest phenocrysts or amygdules filled with later mineral growth.

Uses & applications

Commonly used as crushed stone for asphalt, road base, and concrete aggregate; also used for lithotherapy and stone carving.

Geological facts

Basalt is the most common rock type in the Earth's crust and makes up most of the ocean floor. It is also found on the Moon and Mars.

Field identification & locations

Identified by its fine-grained dark matrix and heavy weight. Look for dark, dense outcrops in volcanic regions or ocean floor samples.

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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)

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Magnetite

Magnetite (Fe3O4)

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