Gemstones P-R : facts & lore

As a qualified gemmologist, I love sharing the science, history and stories behind the stones I use. This page covers gemstones beginning with P–R, including:

• Physical properties (hardness, composition, crystal system)
• Origins and historical uses
• Metaphysical folklore and lore*

PEARLS

What are pearls?
Pearls are formed in clams, oysters and mussels when the organism secretes a substance known as nacre around an irritant in the outer tissue or between the outer tissue and the shell. Only a few species are capable of producing pearls and secreting the nacreous coating that gives pearls their attractive lustre. Nacre also coats the inner surface of shells, where it is known as mother-of-pearl. In most species, nacre forms at a slow rate — approximately 0.6 mm per year.

Natural pearls
Natural pearls form by chance when an irritant enters the oyster. A natural pearl develops in only about 1 in 40 pearl-producing oysters. Due to their slow growth rate and the relatively short lifespan of oysters, large natural pearls are rare and usually not perfectly round.

Found in the Persian Gulf (considered the finest natural pearls in the world), the Gulf of Manaar, the Red Sea, the north and northwest coast of Australia, Burma, Tahiti, New Guinea, Borneo and Venezuela.

Cultured pearls
Cultured pearls grow around a nucleus that has been manually placed within an oyster. This practice dates back to 13th-century China, but was perfected in the early 20th century by the Japanese.

Historically, a round nucleus — usually composed of clam or oyster shell — was placed between the mantle and shell of the oyster and allowed to grow for 2–3 years. In modern cultured pearls, the
nucleus (a bead composed of freshwater clam shell wrapped with a strip of the mollusc’s mantle) is placed within the mantle or gonad of the oyster, away from the shell, allowing it to grow freely.

The size of the resulting pearls depends on the size of the nucleus, the mollusc species, the temperature and chemistry of the water, and the time allowed for growth. Several pearls may be grown in a single oyster, but these will be smaller than if a single nucleus is inserted. Growth periods range from 2 to 7 years, and only approximately 25% produce a cultured pearl. Japan and Australia are significant producers of cultured pearls. Australia uses an indigenous oyster that typically produces large white or silvery pearls.

Cultured black pearls
Black pearls are found in oysters off Peru, Baja California, Panama, certain islands of Indonesia, Micronesia, the Philippines, Okinawa and French Polynesia (Tahiti and adjacent islands). Large-scale production of cultured black pearls has occurred primarily in the latter region. These pearls are notably large, have a high growth rate and display superior lustre.

Freshwater pearls
Natural freshwater pearls form through the same process as other pearls, except they occur in mussels (freshwater) rather than oysters (saltwater).

Cultured freshwater pearls are created by either:

Inserting a small piece of live mantle tissue (from another mussel) directly into the pearl-producing mussel. These pearls are composed entirely of nacre, just like their natural counterparts.

1. Inserting a shape into the mussel in a manner similar to cultured pearl creation, producing “coin” and other shaped pearls.

A single mussel can produce up to 60 pearls at a time.

Special pearl types

Blister pearls form when the oyster or mussel coats the pearl and also coats the shell lining, resulting in a pearl attached to the shell.

Keshi pearls (also known as petal pearls) form when an oyster or mussel rejects and expels the nucleus implanted during cultured pearl production. Because the nucleus has been expelled, the resulting pearl is composed entirely of nacre and often displays wonderful lustre.

Colour of pearls
Natural pearl colours vary from creamy white to yellow, pink, green, lavender, grey and black. Colours are caused by the amount of conchiolin and aragonite present in the nacre and by the quality of the water in which the oyster or mussel lives.

Freshwater pearls’ natural colours include white, cream, lavender, pink, orange, gold and grey. White pearls are often bleached to remove faint undesirable tones. Freshwater pearls are frequently treated (by irradiation or dyeing) to create a rainbow of colours.

Pearl terminology

Lustre — the shiny exterior of the pearl. The way pearls seem to glow from within, based on the depth of reflection.

Bodycolour — the underlying colour of the pearl.

Overtone — a translucent layer of colour. Not all pearls have an overtone.

Iridescent orient — the variable play of colours across the surface of the pearl, like a rainbow. Not all pearls display iridescent orient.

Imitation pearls
Many imitation pearls — made from glass, acrylic or plastic — are available on the market and can look and feel very realistic. Always check product descriptions carefully when purchasing “pearls,” and don’t hesitate to ask the vendor questions. If they can’t answer clearly, consider buying elsewhere.

History & lore
Considered magic charms, symbols of purity and love, or sources of wisdom and power, pearls are among the oldest known gems. They were worn in civilised Middle Eastern and Asian societies as early as
3500 BC. India’s Hindu god Krishna was credited with discovering pearls — taking one from the sea and presenting it to his daughter Pandaïa on her wedding day. Medieval knights wore pearls for protection in battle. The Greeks associated pearls with love and marriage. Ancient Romans saw them as the ultimate symbol of power and wealth — a single pearl earring reportedly funded one Roman general’s political campaign!

PERIDOT

What is peridot?
Peridot belongs to the olivine mineral group. Its name may derive from the Arabic word for “gem,” faridat. In early times, peridot was often grouped with other similarly coloured stones under the name chrysolite. It is mentioned in the Bible under the Hebrew name pitdah and was likely used in the fabled Breastplate of the Jewish High Priest.

An ancient mine on the island of Zabargad in the Red Sea was worked for over 3,500 years before lying undisturbed for centuries — rediscovered at the turn of the 20th century. The largest known cut peridot, weighing 319 carats, came from this mine. Peridot was brought to central Europe by the Crusaders and many were presented to churches as “emeralds.” In Russia, some peridots originated from a meteorite that fell in Siberia in the 18th century!

Where is peridot found?
Australia, Brazil, China, Kenya, Mexico, Pakistan, Sri Lanka, South Africa, Tanzania, Norway and the USA.

Similar stones: Can be confused with chrysoberyl, garnet, emerald, prasiolite, beryl, prehnite and tourmaline.

Metaphysical lore: Peridot is believed to help one understand their destiny, alleviate jealousy and resentment, reduce stress, and combat lethargy with a tonic effect — strengthening metabolism
and benefiting the skin. In ancient times, it was thought to keep away evil spirits.

PRASIOLITE

What is prasiolite?
Prasiolite — from the Greek for “leek-green stone” — is rare in
nature. Most prasiolite on the market is produced by heating
amethyst or citrine, and is often marketed as “green amethyst”
or “greened amethyst.”

PREHNITE

What is prehnite?
Prehnite is named after Dutch Colonel Hendrick von Prehn, who first introduced it to Europe. It is found in Australia, China, Scotland, South Africa and the USA.

Similar stones: Can be confused with apatite, chryoprase, jade, peridot and serpentine.

Metaphysical lore: Prehnite is considered “the crystal that heals the healer.” It is believed to enhance inner knowing, help you always be prepared, calm the environment and bring peace and protection. It is associated with harmony with nature and is valued in Feng Shui for assisting with decluttering and organising. Crystal healers believe it is particularly good for diagnosis.

PYRITE

What is pyrite?
Pyrite can cause sparks when struck against iron — its name comes from the Greek word for “fire.” Due to its gold colour, it is often called “fool’s gold.” Long used for adornment, pyrite jewellery has been found in ancient Greek, Roman and Inca civilisations. Native Americans believed pyrite “mirrors” allowed you to see inside the soul.

Where is pyrite found?
Peru, Bolivia, Mexico, Romania, Sweden, Spain, Italy, France and the USA.

Metaphysical lore: Pyrite is considered an excellent energy shield — deflecting harm and danger and helping you see truth behind facades. It is believed to relieve anxiety and frustration while increasing confidence. Crystal healers associate it with supporting the lungs, digestive and circulatory systems.

QUARTZ – ROSE

What is rose quartz?
Rose quartz is named for its pink colour. It is often crackled and usually turbid. Found in Brazil, Madagascar, India, Mozambique, Namibia, Sri Lanka and the USA.

Similar stones: Can be confused with kunzite, morganite and topaz.

Metaphysical lore: Rose quartz is considered a stone of unconditional love and infinite peace. Crystal healers believe it strengthens the physical heart and circulatory system, alleviates vertigo and may be helpful with Alzheimer’s, Parkinson’s and senile dementia.

QUARTZ – ROCK CRYSTAL

What is rock crystal?
The name “crystal” comes from the Greek word for “ice,” as it was once believed to be eternally frozen. Many myths surround rock crystal — in Japanese myth, quartz formed from the breath of a white dragon; in the first century, the mystic Apollinus of Tyana used quartz to “transport” himself — reportedly dematerialising and reappearing before Caesar Domitian and at the foot of Mt. Vesuvius.

Found worldwide, huge crystals weighing tons have been found — though rarely of cuttable quality. Rock crystal can contain inclusions of goethite,gold, pyrite, rutile and tourmaline. It can be confused with other colourless gems and glass imitations.

Metaphysical lore: Rock crystal is considered a powerful healing and energy amplifier. Crystal healers believe it is a master healer that stimulates the immune system and brings the body into balance. Natural rainbows are often found within quartz crystals, and healers believe this stone draws off negativity and disperses healing energy to the body and environment.

QUARTZ – SMOKEY

What is smoky quartz?
Smoky quartz — also known as morion or cairngorm — gets its colour from natural gamma radiation. Clear (rock crystal) quartz can also be irradiated to produce smoky quartz.

Where is smoky quartz found?
Worldwide, with larger producers including Brazil, Madagascar, Russia, Scotland, Switzerland and Ukraine.

Similar stones: Can be confused with andalusite, idocrase and tourmaline.

Metaphysical lore: Smoky quartz is considered a grounding stone that helps with stress, dealing with difficult times and depression. Crystal healers believe it is effective for ailments of the abdomen, hips and legs.

RHODOCHROSITE

What is rhodochrosite?
Rhodochrosite’s name comes from the Greek word rhodos, meaning “rose coloured.” It is typically found in a massive, opaque form, though transparent crystals are highly prized. The massive form often displays stripes and zigzag bands in pinks and raspberry red.

An important source of rhodochrosite is in Argentina, where it forms as stalagmites in an abandoned Inca silver mine — hence the name “Inca Rose.” It is also found in Chile, Mexico, Peru, South Africa and the USA.

Similar stones: Often confused with rhodonite.

Metaphysical lore: Rhodochrosite is believed to enhance compassion, attract soulmates and encourage spontaneous expression of feelings.

RHODONITE

What is rhodonite?
Rhodonite is named from the Greek word rhodos for “rose.” It typically displays a pink-red colour with black dendritic inclusions of manganese oxide. It is rarely found in a transparent form.

Where is rhodonite found?
Australia, Finland, New Zealand, Japan, England, Canada, Madagascar, Mexico, Russia, Sweden, South Africa, Tanzania and the USA.

Similar stones: Often confused with rhodochrosite.

Metaphysical lore: Rhodonite is considered an emotional balancer, believed to help heal emotional shock and panic, and reduce emotional wounds. It is thought to turn back insults and prevent retaliation. Crystal healers associate it with aiding in the healing of wounds and insect bites.

RHYOLITE

What is rhyolite?
Rhyolite is a fine-grained volcanic rock that cooled too quickly for crystals to form. Its name comes from the Greek word for “stream,” in allusion to the flow banding that can be characteristic. It is sometimes called “rainforest jasper” or “wonderstone.”

Chemically similar to granite, rhyolite often intergrows with quartz, feldspar and plagioclase. Notable deposits are in Australia and the USA, though it is found on all continents.

Metaphysical lore: Rhyolite is believed to represent change, variety and progress. It is thought to enhance creativity, support self-realisation and balance emotions. Crystal healers associate it with increasing self-respect, self-worth and the capacity to love.

RUBY

What is ruby?
The name “ruby” comes from the Latin ruber, meaning “red.” Until the 19th century, many red stones — including spinel and garnet — were also called “ruby.”

The most desirable colour is known as “pigeon’s blood” — a pure red with a hint of blue. As colour is the primary determinant, paler stones may be classified as pink sapphire rather than ruby. Inclusions are common, and colour is often uneven. Heat treatment is frequently used to enhance colour.

Most rubies are found in alluvial deposits. Found in Burma, Thailand, Sri Lanka, Tanzania, Afghanistan, Cambodia, Kenya, Madagascar, Vietnam, Australia, Brazil, India, Malawi, Nepal, Pakistan, USA and Zimbabwe.

Similar stones: Can be confused with garnet, topaz, tourmaline and zircon. Synthetic rubies and imitations are common.

Metaphysical lore: Ruby is considered an energetic stone that encourages a passion for life and motivates, though it can also overstimulate. It is believed to be a stone of abundance, helping retain wealth and passion. Crystal healers associate it with detoxifying the body, blood and lymph, and treating fevers and infectious diseases.

*Disclaimer – Metaphysical & Healing Claims

In keeping with Australian Fair Trading guidelines, no therapeutic claims are made and no medical advice is offered.

The information on metaphysical properties and folklore provided on annettepiper.com is for educational and cultural purposes only. It is not a substitute for professional medical diagnosis or treatment.

We assume no responsibility for the treatment or cure of any illness or disease. If you have a health concern, please consult a qualified healthcare professional.

This content is intended as general information and should not be used for self-diagnosis or as a replacement for medical care.