Pearl
Organic gem made of aragonite, calcite
Rare · CaCO₃ (aragonite) with conchiolin
Grown inside a living mollusc, in layers of nacre (tablets of aragonite interleaved with the organic conchiolin) laid round an irritant: saltwater oysters, some freshwater mussels, more rarely other shellfish. Not a mineral but a gem of animal origin, and soft: 2.5 to 3 on the Mohs scale. Pearls have been cultured since Mikimoto succeeded in Japan in 1893.
Identity
- Formula
- CaCO₃ (aragonite) with conchiolin
- Chemical class
- Carbonate
- Also known as
- Natural pearl, Cultured pearl
- Used in alchemy
- Pearl Powder, Perfect Pearl Powder, River Pearl Grit
Crystallography
- Crystal system
- Orthorhombic
- Habits
- Rounded
- Fracture
- Uneven
Physical properties
- Mohs hardness
- 2.5
- Density
- 2.7 g/cm³
- Luster
- Pearly
- Colors
- white, pink, silver, golden yellow, green, blue, black
- Streak
- white
- Transparency
- Translucent, Opaque
Geology
- Origins
- Sedimentary
- Host rocks
- Limestone and chalk, River gravels and sands
- Associated minerals
- Aragonite, Calcite
- Geography
- French Polynesia (Tuamotu), Australia (Arafura Sea), Philippines, Japan
Classification
- Rarity
- Rare
- Gem quality
- Yes
Arcane properties
- Affinity
- Water, Light
- Effects
- Healing, Scrying
- Planar origin
- Material Plane
Sources
- Pearl. Mindat.org (Hudson Institute of Mineralogy).
- Pearl. Gemdat.org (Hudson Institute of Mineralogy).
- Pearl. Gemological Institute of America, Gem Encyclopedia.
- Pearl Description. Gemological Institute of America, Gem Encyclopedia.
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