igneous

Dalmatian Jasper

Peralkaline Quartz-Feldspar Rock with Arfvedsonite

Hardness: 5.5-7 (Mohs scale), Color: Creamy white to gray with black or dark brown spots, Luster: Vitreous to dull, Crystal Structure: Trigonal/Microcrystalline, Specific Gravity: 2.6-2.7

Hardness: 5

Identified May 29, 2026More igneous →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 5.5-7 (Mohs scale), Color: Creamy white to gray with black or dark brown spots, Luster: Vitreous to dull, Crystal Structure: Trigonal/Microcrystalline, Specific Gravity: 2.6-2.7

Formation & geological history

Dalmatian Jasper is an igneous rock that forms from the slow cooling of magma. The characteristic 'spots' are actually inclusions of arfvedsonite (a sodic amphibole) or rarely tourmaline. It is primarily found in Chihuahua, Mexico.

Uses & applications

Mainly used for lapidary purposes including beads, cabochons, carvings, and ornamental jewelry. It is also popular in holistic practices and stone collecting due to its unique pattern.

Geological facts

Commonly misidentified as a jasper (which is sedimentary), it is actually an igneous rock composed mainly of quartz and feldspar. Its name comes from its resemblance to the Dalmatian breed of dog.

Field identification & locations

Identify by the distinct black spots on a white-tan background; the spots are typically circular and evenly distributed. It is most commonly found in Mexico. Collectors should look for sharp contrast between the matrix and the spots.

Other igneous specimens

See all

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

Dalmatian Jasper

Aplite with Arfvedsonite inclusions

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