# Pearls

> Pearls form inside mollusks and are prized for their luster; they can be natural or cultured, saltwater or freshwater.

- Source: https://www.711grados.com/en/pearls/
- Language: en
- Note: This entry was drafted with the help of AI and is pending review by the author.
- Published: 2026-07-04
- Updated: 2026-07-04
- Translation (es): https://www.711grados.com/es/perlas/
- Author: Sandra Sánchez
- Site: 711 Grados (https://www.711grados.com/)

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Pearls are the only gems that form inside a living creature. A mollusk, such as an oyster or mussel, coats an irritant with layers of nacre and, over time, a pearl is born. Today almost all pearls sold are cultured: a person introduces the nucleus, but the mollusk does the actual forming.

## Properties

- **Composition:** calcium carbonate (aragonite) and an organic substance, conchiolin, in concentric layers of nacre.
- **Hardness:** between 2.5 and 4.5 on the Mohs scale: they scratch easily.
- **Origin:** saltwater (Akoya, Tahitian, South Sea) or freshwater (most cultured pearls)
- **Grading:** luster, shape (round, oval, baroque), surface, color and size.
- **Colors:** white, cream, pink, golden, gray and black, with overtones.

## Uses in jewelry

- Classic strands of knotted pearls.
- Stud or drop earrings.
- Rings, brooches and pendants with a single pearl.
- Baroque pearls in contemporary designer jewelry.

## Pros and cons

### Advantages

- Soft, elegant, timeless glow.
- A wide range of colors and shapes.
- They combine with metals and stones.

### Limitations

- They are soft and sensitive to acids, perfume and sweat.
- The nacre wears over time.
- Glass and plastic imitations exist.

## Care and cleaning

- Put them on last, after makeup and perfume, and take them off first.
- Wipe them after each wear with a soft damp cloth.
- Store them apart in a cloth pouch so they do not scratch.
- Restring on silk thread every few years if worn often.

## See also

- [Mother-of-pearl and shells](https://www.711grados.com/en/mother-of-pearl-and-shells/)
- [Coral](https://www.711grados.com/en/coral/)
- [Amber](https://www.711grados.com/en/amber/)