Nacre Shell
Other Silicates & Gemstones
Nacre, or mother-of-pearl, is the iridescent inner shell layer made by some molluscs. It is an organic-mineral composite of thin aragonite tablets and protein-rich layers, not a mineral species; interference within the layered structure creates its shifting colors.
Identity
- Material or variety
- Nacre (mother-of-pearl)
- Scientific or material identity
- Nacre (mother-of-pearl)
- Classification
- Organic gem material
- Aliases or trade names
- Mother-of-pearl · Mother of pearl
- Composition or formula
- Aragonite CaCO₃ platelets in an organic matrix
- Crystal system or structure
- Aggregate or composite structure
- Geological or manufacturing origin
- Built by a living organism rather than crystallized as a mined gem.
- Mohs hardness
- 2.5 to 4.5
- Specific gravity
- 2.60 to 2.87
Origins
Australia · China · Japan · Philippines · Pacific and Indian oceans
Appearance & optical properties
white shell nacre with pastel iridescence.
History & discovery
People have long cut nacre for ornament and inlay. Pearl oysters, freshwater pearl mussels, and abalones became important commercial shell sources. During the nineteenth century the material appeared widely in decorative arts, while pearl buttons made mother-of-pearl especially widespread around the beginning of the twentieth century.
Uses & care
- Common uses
- Nacre is carved or inlaid in jewelry, buttons, boxes, furniture, mosaics, and musical instruments. The same material forms the lustrous layers of nacreous pearls.
- Handling and cleaning
- Wipe it with a very soft clean cloth. Keep it away from heat, acids, perfume, cosmetics, abrasion, steam, and ultrasonic cleaners, because nacre is soft and can dehydrate, scratch, or crack.
Jewellery
3 pieces of Nacre Shell jewellery. Learners earn each one in DigMyGem by learning words; until then it shows as a silhouette.
Burghley Nef
Jewel
A silver-gilt salt shaped like a ship whose hull is a carved nautilus shell, made in Paris around 1520 and long kept at Burghley House.
Photo: The original uploader was VAwebteam at English Wikipedia ., CC BY-SA 3.0, via Wikimedia Commons 
La Peregrina Pearl
Necklace
A large pear-shaped pearl of nacre found off Panama in the sixteenth century that passed through the Spanish and French crowns before Cartier set it in a necklace.
Pearl of Lao Tzu
Jewel
An enormous irregular mass of nacre taken from a giant clam in the Philippines and often called the largest pearl ever found.
