Basic Properties of Pearls

Pearls are organic gemstones primarily produced inside marine mollusks or freshwater mussels. Their main components include aragonite, organic conchiolin (also known as keratin), water, and trace elements such as sodium, potassium, lithium, magnesium, manganese, iron, and copper.

• Chemical Composition: Calcium carbonate, organic matter (hard proteins), small amounts of water, and trace elements.

• Inorganic Components: Crystalline radial aggregates; crystalline structure.

• Organic Components: Non-crystalline material.

• Color: Ranges from colorless to yellow, pink, green, blue, purple, etc.

• Luster: Pearlescent luster.

• Transparency: Semi-transparent to opaque.

• Optical Properties: Heterogeneous aggregate.

• Refractive Index: 1.53–1.56.

• Relative Density: 2.60–2.85 (varies slightly depending on the type and origin of the pearl).

• Mohs Hardness: 2.5–4.

• Ultraviolet Fluorescence: None to strong, in shades of pale blue, yellow, green, or pink.