What is the Difference Between Pearl and Mother of Pearl

The main difference between pearl and mother of pearl is that pearl is a hard, shiny, spherical mass that is usually creamy white in colour while the mother of pearl is the iridescent substance that creates the inner layer of the shell of some molluscs.

Although both pearl and mother of pearl have the same origins and are considered as organic gemstones, they are two distinct products. Mother of pearl is the iridescent inner layer of mollusc shells while pearls are the hard, round objects found inside some molluscs.

Key Areas Covered

1. What is Pearl
     – Definition, Features
2. What is Mother of Pearl
     – Definition, Features
3. What is the Difference Between Pearl and Mother of Pearl
     – Comparison of Key Differences

Key Terms

Pearl, Mother of Pearl, Gemstones

What is Pearl

A pearl is a hard, shiny, spherical mass that is usually creamy white in colour and highly prized as a gemstone. In fact, it is the only gemstone in the world that comes from a living organism. Pearls form within the shell of a pearl oyster or other bivalve mollusc. Therefore, they are composed of calcium carbonate. Moreover, pearls can come from either salt or freshwater sources. Although there are different colours and shapes in pearls, white and almost perfectly round pearls are the most popular. Traditionally, saltwater pearls were rounder in shape and had a better nacre coating than freshwater pearls, which had irregular shapes.

We can categorize pearls into two basic categories as natural and cultured. Pearls form naturally when a foreign substance slips into the mollusc and the mollusc protects itself by coating the irritant with many layers of a fluid. We call this coating nacre. Natural pearls are extremely rare.

Cultured pearls also go through the same process. However, in cultured pearls, the irritant is a surgically inserted inside the mollusc. This is the basic difference between natural pearls and cultured pearls. High-quality cultured pearls need a sufficient amount of time to form- generally at least 3 years. Lower-quality pearls are taken out of the shell too quickly and have a too-thin coat of nacre. 

What is Mother of Pearl

Mother of pearl is the pearly internal layer present in some mollusc shells. This is also what we call nacre. Mother of pearl specifically refers to the inner shell of the mollusc. It is iridescent, strong, and resilient. It has a distinct multi-coloured effect and a faint glow. Most molluscs produce mother of pearl; therefore, it is not as rare as pearls. Since mother of pearl is more commonly found than pearls, it is less expensive than pearls.

Mother of pearl can be used for fashion, architecture, and other decorative purposes. Unlike pearls, mother of pearl has a flat surface and doesn’t have shape. Moreover, it can be carved and shaped into unique designs.

Difference Between Pearl and Mother of Pearl

Definition

A pearl is a hard, shiny, spherical mass that is usually creamy white in colour while the mother of pearl is the iridescent substance that forms the inner layer of the shell of some molluscs.

Shape

While pearls are usually spherical in shape, mother of pearl doesn’t have a shape since it’s a flat surface.

Formation

Pearls form naturally when a foreign substance slips into the mollusc and the mollusc protects itself by coating the irritant with many layers of a nacre, which over time builds up a spherical pearl. In contrast, the mother of pearl is a thin layer formed on the inner lining of the oyster’s shell. 

Availability

Pearls are much rarer than mother of pearl.

Price

Since natural pearls are rare, they are much more expensive than mother of pearl.

Conclusion

Mother of pearl is the iridescent inner layer of mollusc shells while pearls are the hard, round objects found inside some molluscs. Since the mother of pearl is more commonly found than pearls, it is less expensive than pearls. This is the difference between pearl and mother of pearl.

Reference:

1. “About Pearls.” American Gem Society, Available here.
2. Wickell, Carly. “What Is Mother of Pearl?” The Spruce Crafts, Available here.

Image Courtesy:

1. “Circle south sea pearls” By Auadtbk – Own work (CC BY-SA 3.0) via Commons Wikimedia
2. “Oyster, shell, mother of pearl, gloss, valuable, jewellery, pacific oyster, crassostrea pacifica, crassostrea gigas, animal, creature” (CC0) via Pikist