Opal vs. Pearl — What's the Difference?

A birthstone for those born in October.

A lustrous gemstone formed within mollusks.

A hydrated form of silica with a play-of-color.

A result of layers of nacre deposited around an irritant.

A gemstone sensitive to heat and pressure.

A symbol of purity and elegance.

A precious gemstone known for its iridescence.

A birthstone for those born in June.

A symbol of hope and creativity.

A precious stone requiring gentle care.

Opal is a hydrated amorphous form of silica (SiO2·nH2O); its water content may range from 3 to 21% by weight, but is usually between 6 and 10%. Because of its amorphous character, it is classed as a mineraloid, unlike crystalline forms of silica, which are classed as minerals.

A pearl is a hard, glistening object produced within the soft tissue (specifically the mantle) of a living shelled mollusk or another animal, such as fossil conulariids. Just like the shell of a mollusk, a pearl is composed of calcium carbonate (mainly aragonite or a mixture of aragonite and calcite) in minute crystalline form, which has deposited in concentric layers.

A gemstone consisting of a form of hydrated silica, typically semi-transparent and showing many small points of shifting colour against a pale or dark ground

A hard, lustrous spherical mass, typically white or bluish-grey, formed within the shell of a pearl oyster or other bivalve mollusc and highly prized as a gem

A mineral of hydrated silica.

A person or thing of great worth

A gemstone made of this mineral, noted for its rich iridescence.

Another term for picot

(mineral) A mineral consisting, like quartz, of silica, but inferior to quartz in hardness and specific gravity, of the chemical formula SiO₂·nH₂O.

Form drops resembling pearls

(gemology) A precious gem, an iridescent gemstone found in the opal-silica mineral substrate (potch)

Dive or fish for pearl oysters

A colloquial name used in molecular biology referring to a particular stop codon sequence, "UGA."

A smooth, lustrous, variously colored mass, chiefly of calcium carbonate, formed around a grain of sand or other foreign matter inside the shell of certain bivalve mollusks and valued as a gem.

Any of various lycaenid butterflies of the genus Nesolycaena.

A bead resembling one of these masses.

A mineral consisting, like quartz, of silica, but inferior to quartz in hardness and specific gravity.

Something small and spherical in shape

A translucent mineral consisting of hydrated silica of variable color; some varieties are used as gemstones

Mother-of-pearl; nacre.

One that is highly regarded for its beauty or value.

(Printing) A type size measuring approximately five points.

A yellowish white.

To decorate or cover with pearls or beads resembling pearls.

To make into the shape or color of pearls.

To dive or fish for pearls or pearl-bearing mollusks.

To form beads resembling pearls.

Variant of purl2.

A shelly concretion, usually rounded, and having a brilliant luster, with varying tints, found in the mantle, or between the mantle and shell, of certain bivalve mollusks, especially in the pearl oysters and river mussels, and sometimes in certain univalves. It is usually due to a secretion of shelly substance around some irritating foreign particle. Its substance is the same as nacre, or mother-of-pearl. Round lustrous pearls are used in jewellery.

(figuratively) Something precious.

A capsule of gelatin or similar substance containing liquid for e.g. medicinal application.

Nacre, or mother-of-pearl.

A whitish speck or film on the eye.

A fish allied to the turbot; the brill.

A light-colored tern.

One of the circle of tubercles which form the bur on a deer's antler.

The size of type between diamond and agate, standardized as 5-point.

A fringe or border.

(obsolete) A jewel or gem.

(figurative) A valuable little nugget of information; especially, an aphorism or tip#Etymology 5 that is operationally useful for decision-making.

The clitoris.

To set or adorn with pearls, or with mother-of-pearl.

(transitive) To cause to resemble pearls in shape; to make into small round grains.

(transitive) To cause to resemble pearls in lustre or iridescence.

(intransitive) To resemble pearl or pearls.

(intransitive) To hunt for pearls

To sink the nose of one's surfboard into the water, often on takeoff.

Of the nose of the surfboard: to sink in this manner.

A fringe or border.

A shelly concretion, usually rounded, and having a brilliant luster, with varying tints, found in the mantle, or between the mantle and shell, of certain bivalve mollusks, especially in the pearl oysters and river mussels, and sometimes in certain univalves. It is usually due to a secretion of shelly substance around some irritating foreign particle. Its substance is the same as nacre, or mother-of-pearl.

Hence, figuratively, something resembling a pearl; something very precious.

Nacre, or mother-of-pearl.

A fish allied to the turbot; the brill.

A light-colored tern.

One of the circle of tubercles which form the bur on a deer's antler.

A whitish speck or film on the eye.

A capsule of gelatin or similar substance containing some liquid for medicinal application, as ether.

A size of type, between agate and diamond.

Of or pertaining to pearl or pearls; made of pearls, or of mother-of-pearl.

To set or adorn with pearls, or with mother-of-pearl. Used also figuratively.

To cause to resemble pearls; to make into small round grains; as, to pearl barley.

To resemble pearl or pearls.

To dive or hunt for pearls; as, to go pearling.

A smooth lustrous round structure inside the shell of a clam or oyster; much valued as a jewel

A shade of white the color of bleached bones

A shape that is small and round;

Gather pearls, from oysters in the ocean

A pearl is formed within mollusks due to layers of nacre deposited around an irritant.

Yes, opal has been historically considered a stone of luck and creativity.

Opal is a colorful, iridescent gemstone primarily made of silica.

Pearls can range from white, black, pink, to golden, among other shades.

Pearls symbolize purity, innocence, and wisdom.

Real pearls are typically cooler to touch, have slight imperfections, and a gritty feel when rubbed against teeth.

The finest opals are primarily sourced from Australia.

The play-of-color in opal is due to the diffraction of light off its internal silica spheres.

Cultured pearls are formed with human intervention by placing an irritant inside mollusks, while natural pearls form without any human interference.

Yes, but prolonged exposure to water might damage an opal.

While they can be worn, both opal and pearl are softer gemstones and may require extra care to prevent damage.

Generally, saltwater pearls are more valued due to their luster and roundness, but freshwater pearls have their unique charm.

Opals can lose their play-of-color if they dry out, but they don't change colors like some other gems.

It can take several months to many years, depending on the type and size of the pearl.

Some believe opals promote emotional healing and stimulate creativity, though this is based on folklore.