Gemstone profile and identification guide
Smithsonite
Smithsonite is a zinc carbonate mineral used as a collector and ornamental gemstone material.
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Overview
Smithsonite is a zinc carbonate mineral used as a collector and ornamental gemstone material.
Did you know? Some of the most prized smithsonite colors come from historic Namibia deposits.
Use this profile as a collector reference and educational guide for quick on-page comparison, then validate with the interactive identification system.
Identification
Name: Smithsonite
Scientific classification: Carbonate (Smithsonite)
Hardness: 4.5 Mohs
Transparency: translucent
Lustre: vitreous to pearly
Crystal system: Trigonal
Primary colour: Blue Green
Secondary colour: Green
Colour family: Blues
Botryoidal habit, lower hardness, and zinc-carbonate context are key indicators.
Verification Status
Status: verified-core-fields
Reference priority: GIA, Gem-A, Mindat, International Gem Society
Core identity, locality, and physical-property fields reviewed against standard gemological references.
Trade-name and treatment-sensitive entries include explicit disclosure notes where applicable.
Physical Properties
Hardness category: medium
Hardness value: 4.5 Mohs
Chemical composition: Zinc carbonate (ZnCO3)
Crystal system: Trigonal
Common locations: Namibia, Mexico, Greece, United States, Australia
Learn more: Gem-A gemstone education resources.
Colour Variations
Soft zinc carbonate in attractive pastel to vivid botryoidal colors.
Optical effects: None specified in the current dataset.
Detailed Gemology
Mineral species: Smithsonite
Mineral group: Carbonate group
Chemical formula: Zinc carbonate (ZnCO3)
Mohs hardness: 4.5
Crystal system: Trigonal
Lustre: vitreous to pearly
Transparency: translucent
Streak: White
Cleavage: Perfect rhombohedral cleavage
Fracture: Uneven to subconchoidal
Specific gravity: 4.3-4.5
Refractive index: 1.62-1.85 (strong birefringent range)
Optical phenomena: None typically diagnostic
Colour range: Blue-green, green, pink, yellow, brown
Common inclusions: Botryoidal banding, matrix remnants, cavities
Geological environment: Secondary zinc oxidation zones
Principal mining regions: Namibia, Mexico, Greece, United States, Australia
Important commercial sources: Gem smithsonite is sourced from oxidation zones of zinc ore deposits
Historical significance: Important collector mineral with striking colors.
Common treatments: Stabilization and dyeing may occur.
Synthetic or imitation forms: Dyed carbonates and composites can imitate.
Common look-alikes: Hemimorphite, turquoise, dyed magnesite
Jewellery uses: Used in cabochons, carvings, and collector specimens.
Care recommendations: Relatively soft; avoid abrasion, acids, and aggressive cleaning.
Cross-check profile data with GIA Gem Encyclopedia and Mindat entry for Smithsonite.
Formation
Forms in secondary oxidation zones of zinc-bearing sulfide deposits.
Origin
Gem smithsonite is sourced from oxidation zones of zinc ore deposits
Uses
Best for: Used in cabochons, carvings, and collector specimens.
Ideal uses: Collector cabochons and display material.
Care
Relatively soft; avoid abrasion, acids, and aggressive cleaning.
Need another candidate? Use advanced gemstone search or return to the identification guide.
Related gemstones by colour
Related gemstones by hardness
Commonly confused gemstones
Smithsonite FAQ
How can I identify Smithsonite?
Compare hardness (4.5 Mohs), crystal system (Trigonal), colour profile, and lustre (vitreous to pearly) with your sample. Then cross-check related gemstones listed above.
What colour range does Smithsonite appear in?
Soft zinc carbonate in attractive pastel to vivid botryoidal colors.
Where is Smithsonite commonly used?
Collector cabochons and display material.. For maintenance, follow the care guidance in this profile.
Scientific References
GIA: general gemstone identity (reviewed) - Batch 08 factual verification pass.
Gem-A: gemological terminology and testing references (reviewed) - Batch 08 factual verification pass.
Mindat: mineral species and principal localities (reviewed) - Batch 08 factual verification pass.
International Gem Society: gem trade context and treatment overview (reviewed) - Batch 08 factual verification pass.