Great collectors piece for the rare mineral collector. This specimen is polished on the front and the back is rough.
Larimar: Rough Specimen Polished face Weight: 2846 grams (2.846 Kilo)
Size: 5 x 5.65 x 4.40 inches
Larimar, also called “Stefilia’s Stone”, is a rare blue variety of the silicate mineral pectolite found only in the Dominican Republic, in the Caribbean. Its coloration varies from white, light-blue, green-blue to deep blue.
Larimar is a type of pectolite or a rock composed largely of pectolite, an acid silicate hydrate of calcium and sodium. Pectolite is found in many locations, but larimar has a unique volcanic blue coloration, which is the result of copper substitution for calcium.
Miocene volcanic rocks, andesites and basalts, erupted within the limestones of the south coast of the island. These rocks contained cavities or vugs which were later filled with a variety of minerals, including the blue pectolite. These pectolite cavity fillings are a secondary occurrence within the volcanic flows, dikes, and plugs. When these rocks erode, the pectolite fillings are carried down the slope to end up in the alluvium and the beach gravels. The Bahoruco River carried the pectolite-bearing sediments to the sea. The tumbling action along the streambed provided the natural polishing to the blue larimar, which makes them stand out in contrast to the dark gravels of the streambed.
Larimar Gemological Properties:
Chemical Formula: NaCa2Si3O8(OH)
Crystal Structure: Triclinic pinacoidal
Color: White, blue, green-blue, multicolored
Hardness: Typically 4.5 to 5 (up to 6 for some finely fibrous material)
Refractive Index: 1.59 to 1.65
Density: 2.70 – 2.90
Transparency: Translucent to opaque
Double Refraction or Birefringence: 0.038
Fluorescence: Weak: Green