igneous
Dalmatian Jasper
Dalmatian Stone (Arfvedsonite/Albite Microquartz)
Hardness: 5.5-7 (Mohs); Color: White to cream base with distinct black spots; Luster: Dull to vitreous; Crystal Structure: Trigonal/Monoclinic; Cleavage: None/Indistinct; Specific Gravity: 2.58-2.91
- Hardness
- 5
- Color
- White to cream base with distinct black spots
- Luster
- Dull to vitreous
Identified More igneous →
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Physical properties
Hardness: 5.5-7 (Mohs); Color: White to cream base with distinct black spots; Luster: Dull to vitreous; Crystal Structure: Trigonal/Monoclinic; Cleavage: None/Indistinct; Specific Gravity: 2.58-2.91
Formation & geological history
Formed through the process of igneous cooling where silica-rich fluids permeate a rock matrix. The black spots are clusters of Arfvedsonite crystals set within a feldspar and quartz matrix. Primarily found in Chihuahua, Mexico.
Uses & applications
Used primarily for lapidary work, jewelry (beads, cabochons), metaphysical practice, and ornamental carvings.
Geological facts
Despite its trade name, Dalmatian Jasper is geologically a stone (rock) rather than a true jasper, which is typically a microcrystalline variety of quartz. The black spots are often misidentified as tourmaline, but they are actually the amphibole mineral Arfvedsonite.
Field identification & locations
Identify by the characteristic 'dog-spotted' appearance. It is distinct from other spotted stones due to its cream-white base and deeply embedded, irregular black mineral clumps. Found almost exclusively in mining regions of Mexico.
