mineral

Larimar (blue pectolite)

Pectolite, NaCa₂Si₃O₈(OH), commonly copper-bearing blue variety

AI-generated identification · may be incorrect

Hardness 4.5–5 Mohs; pale sky-blue to turquoise with white clouding and dark inclusions, vitreous to silky luster, typically massive or radiating fibrous crystals, with imperfect cleavage. The polished slice shows characteristic web-like blue-white patterns.

Identified August 25, 2026More mineral →

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Physical properties

Formation & geological history

Forms in cavities and fractures of Miocene volcanic rocks on Hispaniola, where silica- and copper-rich hydrothermal fluids altered basaltic material. Gem-quality larimar is commercially produced almost exclusively near Barahona, Dominican Republic.

Uses & applications

Used for cabochons, jewelry, ornamental slabs, and display specimens; it is too soft for heavily worn jewelry and is not a major construction stone.

Geological facts

Larimar is a trade name rather than a separate mineral species; its blue color is associated mainly with copper substitution. Blue intensity generally increases collector appeal, while brown or black areas are matrix or associated minerals.

Field identification & locations

Identify it by its opaque turquoise-blue color, white fibrous/cloudy veining, softness, and volcanic dark matrix; it is commonly found in Dominican Republic material. Avoid acids, prolonged heat, and ultrasonic cleaning.