Rock Identifier
Blue sodalite-bearing rock (likely sodalite rough) (Sodalite, Na₈(Al₆Si₆O₂₄)Cl₂, possibly in syenite or lapis-lazuli-like matrix) — mineral
mineral

Blue sodalite-bearing rock (likely sodalite rough)

Sodalite, Na₈(Al₆Si₆O₂₄)Cl₂, possibly in syenite or lapis-lazuli-like matrix

AI-generated identification · may be incorrect

Opaque vivid royal-to-denim blue pieces with whitish patches and a dull to glassy luster; typically massive rather than visibly crystalline. Sodalite hardness is about 5.5–6 Mohs, with poor cleavage and specific gravity around 2.2–2.4.

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Physical properties

Opaque vivid royal-to-denim blue pieces with whitish patches and a dull to glassy luster; typically massive rather than visibly crystalline. Sodalite hardness is about 5.5–6 Mohs, with poor cleavage and specific gravity around 2.2–2.4.

Formation & geological history

Forms in silica-poor, sodium-rich alkaline igneous rocks, especially nepheline syenites, through late-stage magmatic crystallization. Most specimens are Precambrian to younger alkaline-rock occurrences; the image alone cannot establish age.

Uses & applications

Used as a decorative and carving stone, beads, cabochons, tumbled stones, and ornamental slabs; attractive material may sell as a lapis-lazuli substitute.

Geological facts

The blue color is caused mainly by sulfur-related color centers. White veining or patches may be calcite or nepheline; abundant pyrite would instead suggest lapis lazuli.

Field identification & locations

Identify by its even blue color, moderate hardness, lack of metallic pyrite, and reaction of any white calcite matrix to dilute acid. Common sources include Canada, Brazil, Namibia, Russia, and Afghanistan; confirm with hardness, streak, and mineralogical testing.