Blue-violet sodalite is an uncommon rock-forming mineral. Feldspathoid mineral Na4Al3Si3O12Cl makes it. High-quality sodalite is a gemstone, sculptural material, and building stone.
Igneous rocks from sodium-rich magmas include sodalite. “Sodalite” comes from this. Quartz and feldspar minerals are rare in these magmas because silicon and aluminum were scarce.
Nepheline, trachyte, and phonolite contain sodalite. Most geologists never encounter these uncommon rocks.
Litchfield, Maine; Magnet Cove, Arkansas; northern Namibia; Golden, British Columbia; Bancroft, Ontario; Kola Peninsula, Russia; and the Ilimaussaq intrusive complex of Greenland are sodalite sources.
Light blue sodalite-rich nepheline syenite. “Sodalite granite” is a rare internal dimension stone. Near Ice River, BC, Canada. Specimen measures 3 inches (7.6 cm).
Feldspathoids include sodalite. Rare aluminosilicate minerals with high calcium, potassium, or sodium. Sodalite, nepheline, leucite, nosean, hauyne, lazurite, cancrinite, and melilite. Igneous rock veins and fractures contain these minerals. Contact metamorphic rocks have them too.
Ice River, British Columbia’s “sodalite granite” up close.
Sodalite Physical Properties
Nepheline, sodalite, and other feldspathoid minerals are blue to blue-violet. With a Mohs hardness of 5.5 to 6, it is transparent and vitreous.
Sodalite has white veining like lapis lazuli. Lapis lazuli often contains sodalite in small proportions. Pyrite disqualifies sodalite.
Crystals of sodalite, a cubic crystal, are rare. Instead of cleavage, it splits conchoidally.
Tumbled sodalite. Pieces displayed are 5/8″ to 1″.
The greatest method to learn about minerals is to handle, analyze, and investigate small specimens. Geology.com sells inexpensive mineral collections. Anna Usova/iStockphoto.
Blue rocks and minerals are rare. Last time you found a bright blue rock? Ever found one in nature? Blue rocks, especially gem-quality ones, are immediately marketable. Sodalite is the only affordable vivid blue material.
Sodalite jewelry is rare. Mall and high-end jewelry stores rarely carry it. Few jewelry shoppers request sodalite. Stores stock consumer favorites.
Craft and lapidary shows sell sodalite jewelry. Sodalite is rarely used in commercial jewelry because cut cabochons vary so greatly in appearance.
Sodalite often mistaken for lapis lazuli. Both materials have white veining and comparable colors. For lapis lazuli fans who can’t afford it, sodalite can be a cheaper substitute.
People love sodalite cabochons, beads, and tumbled stones. They’re inexpensive. Sodalite’s 5.5–6 Mohs hardness limits its application in jewelry. Rings and bracelets will scratch it quickly. Thus, sodalite is best used in earrings, pins, pendants, and other non-abrasive jewelry.