Larimar is a rare, captivating blue gemstone found exclusively in one small region of the Dominican Republic, near the city of Barahona. This unique Caribbean stone is a variety of the mineral pectolite, which is typically colorless or white elsewhere. Its striking coloration, often described as resembling the light-blue and turquoise waters of the sea, has made it highly desirable in the global jewelry market.
The Initial Attempt to Register the Stone (1916)
The existence of the distinct blue stone was first formally documented early in the 20th century. On November 22, 1916, Father Miguel Domingo Fuertes Loren, a Spanish priest residing in the Barahona Parish, submitted a request to Dominican officials seeking permission to explore and exploit a mine containing the blue rock he had discovered.
The request was ultimately rejected, partly because the mineral pectolite was not a known or valued resource in the Dominican Republic. This attempt did not lead to any commercial or scientific recognition of the stone at the time, and it remained largely unknown outside the immediate area for decades.
The Official Discovery and Naming (1974)
The blue stone’s second and definitive discovery occurred in 1974, leading to its current name and worldwide recognition. Dominican artisan Miguel Méndez, along with Norman Rilling, an American Peace Corps volunteer geologist, rediscovered pieces of the stone washed up on a beach at the base of the Bahoruco Mountain Range in Barahona.
Local inhabitants believed the stones were a gift from the sea, but Méndez and Rilling followed the alluvial path of the Bahoruco River upstream. This search led them approximately ten kilometers up the mountain to the main outcrop, which would become the Los Chupaderos mine.
Upon its rediscovery, Méndez gave the mineral its unique trade name, “Larimar,” combining the name of his daughter, Larissa, with the Spanish word for sea, mar. The stone was subsequently identified by the Gemological Institute of America as a new, blue variety of the mineral pectolite, with the chemical formula NaCa₂Si₃O₈(OH).
The Unique Geological Origin
Larimar’s singular blue color and its existence in only one location are due to a specific and rare geological process. The mineral is a type of pectolite, which is a hydrous sodium calcium silicate. Unlike the common white or gray pectolite found elsewhere, the distinct blue and blue-green hues of Larimar are the result of trace amounts of copper.
This blue pectolite formed as a secondary mineral within the cavities, known as vugs, of ancient volcanic rocks. Specifically, Miocene-era basalts and andesites in the Bahoruco region contained these cavities. Hydrothermal fluids, rich in the necessary elements, flowed through the rock and crystallized to form the blue pectolite deposits within these volcanic tubes and fissures. The resulting concentration of copper, substituting for calcium in the mineral structure, is what produces the Caribbean-like coloration, making Larimar a geological rarity.