igneous

Basalt with Quartz Vein

Mafic Igneous Rock (SiO2 filling)

Hardness: 6-7 (quartz) and 5-6 (basalt); Color: Grey-black basalt with white/creamy quartz; Luster: Dull to vitreous; Structure: Fine-grained/aphanitic base; Cleavage: None/conchoidal.

Hardness: 6-7 (quartz) and 5-6 (basalt)
Color: Grey-black basalt with white/creamy quartz
Luster: Dull to vitreous

Identified May 3, 2026More igneous →

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Physical properties

Hardness: 6-7 (quartz) and 5-6 (basalt); Color: Grey-black basalt with white/creamy quartz; Luster: Dull to vitreous; Structure: Fine-grained/aphanitic base; Cleavage: None/conchoidal.

Formation & geological history

Formed through rapid cooling of magnesium-rich and iron-rich lava at the earth's surface. The white section is a quartz vein formed later by hydrothermal fluids filling fractures in the cooled basalt.

Uses & applications

Used in construction as crushed stone or aggregate. High-quality smooth specimens are used as decorative garden stones or in holistic massage (hot stones).

Geological facts

Basalt is the most common rock type on Earth's crust and also makes up most of the surface of the Moon and Mars.

Field identification & locations

Identify by the contrast between the dark, dense volcanic rock and the hard, light-colored mineral vein. Commonly found in coastal areas, riverbeds, and volcanic fields.

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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)

mineral

Blue Apatite

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

mineral

Sodalite

Sodalite - Na8(Al6Si6O24)Cl2

mineral

Magnetite

Magnetite (Fe3O4)

mineral