igneous

Dalmatian Stone

Peralkaline Quartz-Feldspar Rock

Hardness: 5-7.5 (Mohs scale), Color: Creamish-white or pale beige with black spots, Luster: Dull to Vitreous/Greasy, Crystal Structure: Microcrystalline, Cleavage: None/Indistinct, Specific Gravity: 2.6 - 2.8

Hardness: 5-7

Identified March 20, 2026More igneous →

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Physical properties

Formation & geological history

Formed through volcanic activity that creates a dense peralkaline igneous rock. The light matrix is largely composed of feldspar and quartz, while the black spots are crystals of black arfvedsonite (amphibole). Common geological ages vary, but many specimens are from the Phanerozoic eon.

Uses & applications

Primarily used for ornamental purposes, fashion jewelry (beads, cabochons), carving figurines, and as a popular semi-precious stone for gemstone collectors and metaphysical enthusiasts.

Geological facts

Commonly mislabeled as 'Dalmatian Jasper', it is not actually a jasper (a variety of chalcedony) but an igneous rock. The black spots were long mistaken for tourmaline until scientific analysis confirmed they are actually arfvedsonite.

Field identification & locations

Can be identified in the field by its distinctive white-to-tan background peppered with distinct black spots. It is almost exclusively mined in Chihuahua, Mexico. For collectors, authenticity can be verified by the lack of traditional jasper graining and the specific appearance of the amphibole spots.

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