igneous
Dalmation Stone
Peralkaline Rock (SiO2 with Arfvedsonite)
Hardness: 5.5-7 (Mohs scale), Color: Cream/grey with black spots, Luster: Vitreous to dull, Crystal Structure: Microcrystalline, Cleavage: None visible
- Hardness
- 5
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Physical properties
Hardness: 5.5-7 (Mohs scale), Color: Cream/grey with black spots, Luster: Vitreous to dull, Crystal Structure: Microcrystalline, Cleavage: None visible
Formation & geological history
Formed from the slow cooling of magma under the Earth's surface, creating a peralkaline rock primarily composed of feldspar and quartz with black spots of arfvedsonite. Most specimens are from Chihuahua, Mexico.
Uses & applications
Primarily used for tumbling, decorative cabochons, beads for jewelry, and as a pocket stone for collectors.
Geological facts
Despite being commonly called 'Dalmatian Jasper', it is not actually a jasper (sedimentary) but an igneous rock. The black spots are minerals like arfvedsonite, not tourmaline as often misidentified.
Field identification & locations
Identified by its signature 'dalmatian' spot pattern on a pale cream or off-white background. Look for a smooth, matte to waxy polish in tumbled pieces.
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