igneous
Dalmatian Jasper
Peralkaline Quartz-Feldspar Porphyritic Rock (Dalmatian Stone)
Hardness: 5.5-7 (Mohs); Color: White to cream base with black circular spots and brown earthy patches; Luster: Dull to vitreous; Crystal Structure: Monoclinic/Orthorhombic (Microcrystalline); Specific Gravity: 2.60-2.65.
- Hardness
- 5
- Luster
- Dull to vitreous
Identified More igneous →
Explore Dalmatian Jasper in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 5.5-7 (Mohs); Color: White to cream base with black circular spots and brown earthy patches; Luster: Dull to vitreous; Crystal Structure: Monoclinic/Orthorhombic (Microcrystalline); Specific Gravity: 2.60-2.65.
Formation & geological history
Formed during volcanic activity as a peralkaline rock cooling quickly on the Earth's surface. It primarily originates from Chihuahua, Mexico, where it crystallized from magma into microcrystalline quartz and feldspar containing iron-rich arfvedsonite.
Uses & applications
Primarily used in the jewelry industry for beads, cabochons, and tumble stones. It is also popular in the metaphysical and lapidary collecting communities for carving small figurines and spheres.
Geological facts
Despite its trade name 'Dalmatian Jasper', it is not actually a jasper (which is sedimentary) but an igneous rock consisting of feldspar, quartz, and black spots formed by the mineral Arfvedsonite. It is named after the Dalmatian dog breed due to its spotted appearance.
Field identification & locations
Identify in the field by its distinct cream-white matrix with evenly distributed black spots; it will not react to acid and is hard enough to scratch glass. It is almost exclusively mined in Mexico. Collectors should look for a uniform pattern of spots.
