gemstone

Blue chalcedony cabochon, possibly Larimar

Chalcedony (microcrystalline quartz, SiO₂); if genuine Larimar, blue pectolite, NaCa₂Si₃O₈(OH)

AI-generated identification · may be incorrect

Polished oval cabochon with pale blue-white color and waxy to vitreous luster; quartz chalcedony is Mohs 6.5–7, while pectolite is about 4.5–5. Crystal grains are microscopic, so cleavage is absent or indistinct; the image is insufficient for definitive identification.

Identified August 14, 2026More gemstone →

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At a glance

Common name: Blue chalcedony cabochon, possibly Larimar
Scientific name: Chalcedony (microcrystalline quartz, SiO₂); if genuine Larimar, blue pectolite, NaCa₂Si₃O₈(OH)
Category: gemstone
Identified: August 14, 2026
Method: Standard

AI Estimated Value

About $10–$75 for ordinary blue chalcedony cabochons; approximately $30–$300+ for attractive genuine Larimar, depending on color, pattern, size, and workmanship.

Not an official valuation

AI estimate for general interest only — not an appraisal. Actual value depends on condition, provenance, and market demand. Verify with a professional before buying, selling, or insuring.

This identification was generated by AI and may contain errors. Verify important details before relying on them — and never use an AI result to judge whether a specimen is safe to handle. Read the full disclaimer

Physical properties

Formation & geological history

Chalcedony forms from silica-rich groundwater filling cavities and fractures, commonly in volcanic rocks; pectolite Larimar forms hydrothermally in young volcanic rocks. The setting is generally Cenozoic, but exact age depends on locality.

Uses & applications

Used in rings, cabochon jewelry, carvings, and ornamental objects. Larimar-quality material can command a premium, while ordinary blue chalcedony is widely affordable.

Geological facts

Larimar typically shows distinctive cloudlike blue-and-white patterns and is found commercially only in the Dominican Republic. Similar-looking dyed chalcedony, blue opal, and glass are common substitutes.

Field identification & locations

Check for natural patterning, a cool feel, and a smooth conchoidal surface; test hardness and inspect under magnification, but avoid destructive tests on jewelry. Common chalcedony sources include Brazil, India, Turkey, and Madagascar; Larimar comes from Barahona, Dominican Republic.