Dalmatian Jasper
Dalmatian Stone (a porphyritic microgranite) · Semi-Precious Gemstone / Decorative Stone
Crystal System
Trigonal/Monoclinic; typically found in massive, igneous form within a microcrystalline matrix.
Mineral Group
Silicates (specifically a mixture of Tectosilicates and Inosilicates)
Chemical Formula
SiO2 (Quartz) with KAlSi3O8 (Feldspar) and Na2(Mg,Fe)3Al2Si8O22(OH)2 (Arfvedsonite)
Formation Process
Igneous; it forms when magma cools and solidifies, specifically as a microgranite where the black spots of Arfvedsonite crystallize within a felsic matrix.
About This Crystal
Opaque, tumbled stone with a creamy-white to light gray background speckled with distinct, rounded black-to-dark brown spots. It has a vitreous to earthy luster and a smooth, polished surface in this specimen.
Physical Characteristics
Color: White/Cream with black spots; Streak: White; Cleavage: None (massive); Fracture: Uneven to conchoidal; Specific Gravity: 2.6-2.7; Fluorescence: Occasionally weak blue or orange.
Optical Properties
Refractive Index: Approx. 1.54-1.55 (aggregate); Birefringence: None (opaque); Luster: Vitreous when polished; Non-pleochroic and singly refractive in aggregate form.
Hardness & Durability
Origin Region
Chihuahua, Mexico (primary source). Forms in igneous volcanic environments.
Hardness & Durability
Mohs Hardness: 5.5 to 7; Toughness: High; generally durable for jewelry but softer than pure quartz due to feldspar content.
Care & Maintenance
Clean with warm soapy water and a soft cloth; avoid harsh chemicals and ultrasonic cleaners which may penetrate micro-fissures. Store away from harder stones like diamonds.
Rarity & Value
Common; very affordable. Value is determined by the contrast and distribution of spots. Often dyed various colors (blue, green, red) for the bead market.
Special Characteristics
Features 'spotted' inclusions of the mineral Arfvedsonite which create the signature 'dalmatian dog' appearance. Distinctive porphyritic texture.
Lore & History
Named for its resemblance to the Dalmatian dog breed. In metaphysical lore, it is considered a grounding stone that encourages playfulness and joy, often used to help with animal communication or overcoming fears.