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Gemstone profile and identification guide

Pearl

Pearl is an organic gem formed by mollusks, represented in trade by both natural and cultured products.

3 Mohs White, Cream Organic Gem Material (Natural/Cultured Pearl Category)
Pearl

Overview

Pearl is an organic gem formed by mollusks, represented in trade by both natural and cultured products.

Did you know? Most pearls in modern jewelry are cultured rather than natural.

Use this profile as a collector reference and educational guide for quick on-page comparison, then validate with the interactive identification system.

Identification

Name: Pearl

Scientific classification: Organic Gem Material (Natural/Cultured Pearl Category)

Hardness: 3 Mohs

Transparency: opaque

Lustre: pearly

Crystal system: Biogenic aragonite/calcite aggregate

Primary colour: White

Secondary colour: Cream

Colour family: Whites & Neutrals

Type and treatment must be disclosed; surface and X-ray methods support classification.

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 entries include conservative composition and treatment disclosures where needed.

Physical Properties

Hardness category: soft

Hardness value: 3 Mohs

Chemical composition: Calcium carbonate with conchiolin

Crystal system: Biogenic aragonite/calcite aggregate

Common locations: Freshwater and marine pearl cultivation regions globally

Learn more: Gem-A gemstone education resources.

Colour Variations

General pearl category covering natural and cultured pearls in multiple body colors.

Optical effects: Orient

Detailed Gemology

Mineral species: Biogenic pearl material

Mineral group: Organic gem materials

Chemical formula: Calcium carbonate with conchiolin

Mohs hardness: 3

Crystal system: Biogenic aragonite/calcite aggregate

Lustre: pearly

Transparency: opaque

Streak: White

Cleavage: Not applicable

Fracture: Uneven

Specific gravity: 2.60-2.85

Refractive index: Common spot values near 1.53

Optical phenomena: None typically diagnostic

Colour range: White, cream, pink, silver, gold, black

Common inclusions: Growth features, fractures, and matrix/inclusion structures as applicable

Geological environment: Species-dependent; see formation process

Principal mining regions: Freshwater and marine pearl cultivation regions globally

Important commercial sources: Pearl is a broad category requiring type disclosure (natural, freshwater cultured, or saltwater cultured)

Historical significance: Recognized in modern gem and mineral trade contexts.

Common treatments: Bleaching, dyeing, and luster enhancement are common.

Synthetic or imitation forms: Imitations may exist depending on material category.

Common look-alikes: Species-dependent look-alikes in trade.

Jewellery uses: Used in strands, earrings, pendants, and fine jewelry.

Care recommendations: Soft and chemical-sensitive; avoid perfume, acids, and dry heat.

Cross-check profile data with GIA Gem Encyclopedia and Mindat entry for Pearl.

Formation

Concentric nacre deposition around an irritant or implanted nucleus/tissue.

Origin

Pearl is a broad category requiring type disclosure (natural, freshwater cultured, or saltwater cultured)

Uses

Best for: Used in strands, earrings, pendants, and fine jewelry.

Ideal uses: Classic jewelry with careful wear and storage.

Pearl FAQ

How can I identify Pearl?

Compare hardness (3 Mohs), crystal system (Biogenic aragonite/calcite aggregate), colour profile, and lustre (pearly) with your sample. Then cross-check related gemstones listed above.

What colour range does Pearl appear in?

General pearl category covering natural and cultured pearls in multiple body colors.

Where is Pearl commonly used?

Classic jewelry with careful wear and storage.. For maintenance, follow the care guidance in this profile.