Gemstone profile and identification guide
The character of Larimar comes through in its aqua, blue, cyan / blue-green, green, and brown colour and the way that colour interacts with a silicate structure. That combination of aqua body colour, 6.5 Mohs hardness, and vitreous lustre is what usually makes it recognisable in practice. The secondary blue note often matters more than people expect when separating it from lookalikes.
The character of Larimar comes through in its aqua, blue, cyan / blue-green, green, and brown colour and the way that colour interacts with a silicate structure. That combination of aqua body colour, 6.5 Mohs hardness, and vitreous lustre is what usually makes it recognisable in practice. The secondary blue note often matters more than people expect when separating it from lookalikes.
Use this profile as a collector reference and educational guide for quick on-page comparison, then validate with the interactive identification system.
Name: Larimar
Scientific classification: Inosilicate (Pectolite Variety)
Hardness: 4.75 Mohs
Transparency: translucent to opaque
Lustre: vitreous to silky
Crystal system: Triclinic
Primary colour: Aqua
Secondary colour: Blue
Colour family: Blues & Cyans
A practical identification pass begins with the visible basics: transparent transparency, vitreous lustre, 6.5 Mohs hardness, and a hexagonal crystal system. The interaction between aqua and blue tones is more useful than the primary colour alone when comparing candidates. Useful side-by-side comparisons include Topaz, Moonstone, Peridot.
Status: verified-core-fields
Reference priority: GIA, Gem-A, Mindat, International Gem Society
Core identity fields reviewed against consensus gemological references (GIA/Gem-A/Mindat/IGS).
Some market- and locality-level details may still require citation-grade source notes for publication workflows.
Hardness category: medium
Hardness value: 4.75 Mohs
Chemical composition: Sodium calcium silicate hydroxide [NaCa2Si3O8(OH)]
Crystal system: Triclinic
Common locations: Dominican Republic (Barahona Province)
Learn more: Gem-A gemstone education resources.
Larimar sits in the blues & cyans grouping here, usually reading first as aqua with blue appearing as a secondary note or modifier.
Optical effects: None specified in the current dataset.
Mineral species: Pectolite (larimar variety)
Mineral group: Pectolite (inosilicate)
Chemical formula: Sodium calcium silicate hydroxide [NaCa2Si3O8(OH)]
Mohs hardness: 4.75
Crystal system: Triclinic
Lustre: vitreous to silky
Transparency: translucent to opaque
Streak: White
Cleavage: Good in one direction
Fracture: Uneven to splintery
Specific gravity: 2.70-2.90
Refractive index: 1.59-1.63
Optical phenomena: None commonly reported
Colour range: Aqua, Blue, Cyan / Blue-Green, Green, Brown
Common inclusions: Calcite veins, cavities, manganese-bearing colour zones
Geological environment: Larimar occurs in Hydrothermal alteration cavities within basaltic volcanic rocks. Its Triclinic structure reflects the pressure-temperature conditions of those host rocks, with notable occurrences in Dominican Republic (Barahona Province).
Principal mining regions: Dominican Republic (Barahona Province)
Important commercial sources: Larimar is commercially sourced only from the Dominican Republic
Historical significance: Commercially introduced in the 20th century from the Dominican Republic.
Common treatments: Stabilization and waxing are common.
Synthetic or imitation forms: No true synthetic larimar; dyed magnesite and glass are common imitations.
Common look-alikes: Dyed howlite, dyed magnesite, blue calcite
Jewellery uses: Larimar is used chiefly for A good fit for collectors and jewellers looking for visible character without needing the highest hardness category.. In the trade it is commonly fashioned as faceted stones, calibrated cuts, and higher-clarity collector pieces, with Mohs hardness 4.75 guiding suitable jewellery applications.
Care recommendations: Larimar should be cleaned with lukewarm water, mild soap, and a soft brush. At Mohs 4.75 in the Triclinic system, avoid steam cleaners, harsh chemicals, and high-impact wear. Protect cleavage directions from sharp knocks during wear and setting.
Cross-check profile data with GIA Gem Encyclopedia and Mindat entry for Larimar.
Larimar is a Pectolite (larimar variety) material with chemistry Sodium calcium silicate hydroxide [NaCa2Si3O8(OH)]. It develops in Hydrothermal alteration cavities within basaltic volcanic rocks, and economically significant production is associated with Dominican Republic (Barahona Province).
Larimar is commercially sourced only from the Dominican Republic
Best for: Larimar is used chiefly for A good fit for collectors and jewellers looking for visible character without needing the highest hardness category.. In the trade it is commonly fashioned as faceted stones, calibrated cuts, and higher-clarity collector pieces, with Mohs hardness 4.75 guiding suitable jewellery applications.
Ideal uses: A good fit for collectors and jewellers looking for visible character without needing the highest hardness category.
Larimar should be cleaned with lukewarm water, mild soap, and a soft brush. At Mohs 4.75 in the Triclinic system, avoid steam cleaners, harsh chemicals, and high-impact wear. Protect cleavage directions from sharp knocks during wear and setting.
Need another candidate? Use advanced gemstone search or return to the identification guide.
Compare hardness (4.75 Mohs), crystal system (Triclinic), colour profile, and lustre (vitreous to silky) with your sample. Then cross-check related gemstones listed above.
Larimar sits in the blues & cyans grouping here, usually reading first as aqua with blue appearing as a secondary note or modifier.
A good fit for collectors and jewellers looking for visible character without needing the highest hardness category.. For maintenance, follow the care guidance in this profile.
GIA: general gemstone identity (reviewed) - Reviewed as a direct core gemstone profile.
Gem-A: gemological education and terminology (reviewed) - Reviewed as a direct core gemstone profile.
Mindat: mineral species and locality index (reviewed) - Reviewed as a direct core gemstone profile.
International Gem Society: collector-facing gem reference (reviewed) - Reviewed as a direct core gemstone profile.
