igneous

Kimberlite with Diamond

Kimberlite (Diamond formula: C)

Hardness: 10 (diamond), 6-7 (matrix); Color: Bluish-grey to dark green (matrix), clear (crystal); Luster: Adamantine (diamond), earthy (matrix); Crystal structure: Isometric; Cleavage: Perfect octahedral (diamond)

Hardness: 10 (diamond), 6-7 (matrix)
Color: Bluish-grey to dark green (matrix), clear (crystal)
Luster: Adamantine (diamond), earthy (matrix)

Identified May 19, 2026More igneous →

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Physical properties

Formation & geological history

Formed deep within the Earth's mantle (150-450km) and transported to the surface via explosive volcanic eruptions creating vertical conduits called pipes. Age ranges from billions to millions of years old.

Uses & applications

Primarily mined for industrial diamonds used in cutting tools and gem-quality diamonds for fine jewelry.

Geological facts

Kimberlite is named after the town of Kimberley in South Africa. Only about 1 in 200 kimberlite pipes contain economic concentrations of diamonds.

Field identification & locations

Identify by 'Blue Ground' appearance and the presence of indicator minerals like pyrope garnet or chromium diopside. Found in South Africa, Russia, Canada, and Australia.

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)

mineral

Sodalite

Sodalite - Na8(Al6Si6O24)Cl2

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Blue Apatite

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

mineral

Magnetite

Magnetite (Fe3O4)

mineral