A Pectolite found only in the Dominican Republic, Larimar is a semi-precious stone that adheres to a Triclinic system of crystal formation. Its chemical structure is NaCa2(Si3O8)(OH); it is characterized by its blue coloration. There is some contention as to why this occurs: the common assumption is that this is caused by copper inclusions spread throughout the mineral, although it has been suggested the coloration is the effect of Rayleigh scattering. The deeper the blue, the more valuable the mineral, culminating in a fierce Azure variety known as Volcanic Blue.
The stone was named in 1974, when a Dominican, Miguel Méndez, and a Peace Corps volunteer, Norman Rilling, discovered pieces scattered along the beach in the province of Barahona. Méndez, combining his daughter’s name (Larissa) with the Spanish word for sea (Mar), coined the term Larimar. It is a 4.5-5 on the Mohs hardness scale; when sold as jewelry it is often Cabochon cut due to its relative softness.