igneous

Dalmatian Stone

Peralkaline Quartz-Feldspar Porphyry with Arfvedsonite

Hardness: 5.5-7 (Mohs scale); Color: Creamy white to pale gray background with distinct black orbicular spots; Luster: Vitreous to dull; Crystal structure: Monoclinic/Triclinic (feldspar matrix with amphibole inclusions); Specific gravity: ~2.5 - 2.8.

Hardness: 5
Luster: Vitreous to dull

Identified March 25, 2026More igneous →

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Physical properties

Formation & geological history

An igneous rock formed from slowly cooling magma deep within the Earth's crust. It is primarily found in the state of Chihuahua, Mexico. Its age is generally associated with Tertiary volcanic activity in the region.

Uses & applications

Primarily used for ornamental purposes, including beads, cabochons, polished spheres, and decorative carvings. It is popular in the metaphysical community and used in low-cost costume jewelry.

Geological facts

Commonly misidentified as 'Dalmatian Jasper' despite being an igneous rock rather than a sedimentary jasper. The black spots were long thought to be tourmaline, but recent chemical analysis has identified them as the rare amphibole mineral Arfvedsonite.

Field identification & locations

Identify by its unique 'dog-like' spotted appearance and the lack of traditional jasper grain. It is most commonly found in Mexico. Collectors should look for high contrast between the white matrix and dark, sharp black spots.

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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)

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Sodalite

Sodalite - Na8(Al6Si6O24)Cl2

mineral

Magnetite

Magnetite (Fe3O4)

mineral