Rectangular larimar cabochons from the Dominican Republic. Caribbean blue with characteristic white veins of Dominican pectolite. Nominal dimensions 30×20 mm. Selected stock from a wholesale lapidary market.
Piece Details
| Mineral |
Larimar (blue pectolite, NaCa₂Si₃O₈OH) |
| Dimensions |
30×20 mm nominal (tolerance ±0.5 mm) |
| Shape and back |
Rectangular, flat back |
| Finish |
Mirror polish |
| Hardness |
4.5-5 Mohs — we recommend a closed bezel setting to protect the edges; avoid daily wear rings without side protection |
| Origin |
Dominican Republic (sole worldwide source) |
| Treatment |
Untreated |
| Piece type |
Available in lot |
About this specific piece
The rectangular 30×20 mm format is unusual for larimar: most of the market offers ovals and freeform shapes. A rectangular bezel requires greater precision in mounting construction, especially at the corners, where the metal must bend without creating tension on the stone.
Dominican blue varies between light sky blue and volcanic blue depending on the extraction area. The white veins are calcium inclusions that form the patterns distinguishing each piece from others — no two larimars are exactly alike.
What kind of mounting it works for
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Rectangular bezel setting (925 silver) — straight bezel construction requires reinforced corners; it is a more demanding goldsmithing exercise than oval but produces a contemporary and clean result.
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Geometric pendants — the rectangular format fits minimalist straight-line designs.
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Geometric wire wrap — possible with rectangular wrapping techniques that maintain visible geometry.
Larimar in lapidary tradition
Larimar was mineralogically identified in 1974 by Dominican geologist Miguel Méndez, although local communities had known about the blue stone appearing in rivers long before. Its geographical exclusivity — it only exists in a single active mine in the Bahoruco mountains — makes it one of the most localized minerals in the world. In Caribbean tradition, larimar is associated with the serenity of the sea and clear communication; some artisans call it the "Atlantis stone" for its oceanic color.
The symbolic properties attributed to minerals belong to cultural and historical traditions. They are shared for educational purposes, not as medical advice or a substitute for professional care.
How to recognize genuine larimar
Genuine larimar has a pattern of white veins on blue that resembles ocean waves — it is not a solid or uniform blue color. The most common imitations are dyed white pectolite and blue howlite: howlite has a more porous matte texture and the blue appears excessively uniform. The hardness of 4.5-5 Mohs is low — a steel key will easily scratch it.
Frequently asked questions
Is it authentic Dominican larimar?
Yes. Stock from the Dominican Republic, the sole worldwide source. No detectable treatment. Statement based on lapidary observation; does not include formal gemological certification.
Which setting is most suitable?
Custom-built closed bezel in 925 silver. The 4.5-5 Mohs hardness requires side protection; prong settings leave edges exposed to impacts.
Are the dimensions exact?
30×20 mm nominal with a tolerance of ±0.5 mm. As it is uncalibrated industrial lapidary stock, variation is expected.
What makes each piece different?
The pattern of white veins is unrepeatable: it depends on how the blue and white pectolite crystallized in the volcanic basalt.
How to care for it?
Larimar is sensitive to skin oils and can lose its luster. Clean with a soft, dry cloth. Avoid prolonged saltwater exposure. More at jewelry care.
See also: cabochon collection · handmade rings.
