Larimar
Almost every gemstone is found in several countries. Larimar is found in one place: a small area in the Barahona province of the Dominican Republic. Not "mostly" — only.
What is larimar?
Larimar is a blue variety of pectolite, a sodium calcium silicate. Pectolite itself is common and usually white or grey; the blue occurs where copper substituted into the structure as the mineral crystallised in volcanic cavities. That combination of conditions has been found nowhere else.
It was described scientifically only in the 1970s, which by gemstone standards is yesterday. The name is a coinage — a local man's daughter's name joined to mar, the sea.
What causes larimar's blue-and-white pattern?
Larimar's characteristic look is pale blue broken by white, in patches that read as light on shallow water. That patterning is the fibrous pectolite structure showing through; the whiter areas are simply where less copper was present. The most valued material is a deep, even volcanic blue with fine white webbing rather than large white blocks.
How do you judge a good larimar?
Depth and evenness of blue first, then the balance of the pattern. Greenish or grey casts are common in lower grades. Because the supply is geographically fixed and the top grades are a small fraction of output, price climbs steeply with colour saturation in a way it does not for stones with many sources.
Does larimar fade in sunlight?
Worth stating plainly: larimar's colour can fade with prolonged exposure to strong sunlight and heat. This is a real, documented behaviour, not a precaution copied from other stones. A piece worn day to day is fine. One left on a windowsill or a car dashboard is not.
Is larimar durable enough for daily wear?
Mohs 4.5 to 5 — soft, in the same territory as turquoise. It scratches easily and should be set with protection. Cabochon cuts in bezels, not exposed edges.
How do you care for larimar?
Warm water, mild soap, soft cloth, dried at once. No ultrasonic, no steam, no solvents. Store it out of direct light, which is the one instruction people skip.