igneous

Granite Pebble (Salt and Pepper Granite)

Phaneritic Felsic Igneous Rock (primarily Quartz, Feldspar, and Biotite/Amphibole)

Hardness: 6-7 on Mohs scale; Color: Mottled grey, white, and black; Luster: Dull to vitreous; Crystal structure: Phaneritic (coarse-grained visible crystals); Cleavage: Inherent to mineral components (perfect in feldspar/mica, none in quartz).

Hardness: 6-7 on Mohs scale
Color: Mottled grey, white, and black
Luster: Dull to vitreous

Identified March 16, 2026More igneous →

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Physical properties

Formation & geological history

Formed through the slow crystallization of magma below the Earth's surface (intrusive). This specific pebble shape is the result of mechanical weathering and water erosion, likely in a riverbed or coastal environment.

Uses & applications

Used widely in construction (aggregate, countertops, monuments), landscaping, and as a durable material for high-traffic surfaces.

Geological facts

Granite makes up a large portion of the Earth's continental crust. The 'salt' refers to the light-colored quartz and feldspar, while the 'pepper' refers to dark minerals like biotite mica or hornblende.

Field identification & locations

Identify by its interlocking granular texture ('salt and pepper' look) and high hardness (will scratch glass). Common globally in mountainous regions and glacial deposits. For collectors, look for unique mineral inclusions or high-polish potential.

Other igneous specimens

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Blue Apatite

Fluorapatite (Ca5(PO4)3F)

mineral

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

Sodalite

Sodalite - Na8(Al6Si6O24)Cl2

mineral

Blue Apatite

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

mineral

Magnetite

Magnetite (Fe3O4)

mineral