Dalmatian Stone (Dalmation Jasper)

Physical Properties

Hardness: 5-7.5 Mohs scale; Color: Creamy white to green (dyed) with black spots; Luster: Dull to Vitreous; Crystal Structure: Microcrystalline; Specific Gravity: 2.58-2.91

Formation & Geological History

Formed as an igneous rock, specifically an alkali-rich aplite. The black spots are inclusions of the mineral arfvedsonite (often misidentified as tourmaline or hornblende) that crystallized alongside feldspar and quartz from cooling magma.

Uses & Applications

Primarily used for decorative purposes, beads, cabochons, metaphysical crystals, and jewelry. It is highly valued in lapidary for its unique pattern.

Geological Facts

Despite being commercially called 'Dalmation Jasper', it is not actually a jasper. Jasper is a sedimentary chert, whereas this stone is an igneous rock (aplite). The specimens in the image appear to be dyed green, as the natural background color is usually off-white or gray.

Field Identification & Locations

Identify by its distinctive polka-dot pattern. Natural specimens are found almost exclusively in Chihuahua, Mexico. Field identification involves checking for the characteristic black arfvedsonite needle-like clusters against a lighter feldspar/quartz matrix.

Identified on: 5/2/2026

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