Rock Crystal: Meaning, Symbolic Properties, Care

What is rock crystal?

Rock crystal is the colourless and transparent variety of quartz. Quartz, with the formula SiO2 (silicon dioxide), is the most widespread mineral in the Earth's crust: it makes up sand, a large part of granite and many other rocks. When it grows freely in a cavity, it forms beautiful six-sided crystals ending in a point, very clear: this is rock crystal.

Its hardness is 7 on the Mohs scale: harder than a knife blade, it scratches glass and withstands daily use. It is found in the Alpine massifs (the Oisans, in Isère, is famous for its crystals), in Brazil, which has produced the largest crystals known, in Madagascar, and in the United States (Arkansas, or Spruce Pine, in North Carolina, known for its exceptional purity).

The word "crystal" comes from the Greek krustallos, which meant ice: according to an old idea reported notably by Pliny the Elder, rock crystal was ice hardened by the cold to the point that it no longer melted. We now know it is quartz. The word "quartz" itself, of uncertain origin, was used in the Middle Ages for all crystals; it was the mineralogist Georgius Agricola who restricted it to this species.

A crystal between technical uses and beliefs

Quartz has a remarkable property: it is piezoelectric, meaning it produces a small electric voltage when compressed. This is why it has long been used in watches, clocks and many electronic devices. For this purpose, synthetic quartz has been manufactured in laboratories since the mid-20th century.

Long before that, clear crystals served as gems, cups and spheres for gazing into in many cultures. Their purity made them, almost everywhere, a symbol of light and clarity.

Traditional symbolism

The symbolism belongs to tradition and culture, not to science.

• Its transparency links it to clarity, purity and light.
• In modern usage it is sometimes nicknamed the "universal stone": it is credited with the ability to "amplify" the intentions of the person holding it. This is an idea from contemporary lithotherapy, which has not been demonstrated.
• It is used as a focus for concentration in meditation, and as a "neutral stone" to combine with others.

Traditional correspondences

How to use it

• As a point or cluster: to place on a desk or shelf, for its beauty and light.
• As a tumbled stone or jewellery: pendant, ring, beaded bracelet. See our guide to stone jewellery.
• In meditation: held in the hand or placed in front of you, as a point of focus.
• In combination: placed at the centre of a group of stones, by tradition.
• As a sphere: for contemplation; see the stones and minerals range.

Care and cleansing

• Water: lukewarm water, mild soap, a soft brush; dry with a cloth. It has no trouble with water.
• Sun: clear quartz does not fade, but a transparent piece, especially a sphere or a point, can focus light like a magnifying glass. Never leave it near a sunny window beside paper, fabric or curtains.
• Knocks: despite its hardness, a point can break if dropped.
• Thermal shock: avoid plunging a cold stone into hot water.
• Symbolic cleansing: smoke, running water, moonlight. See the guide to cleansing and recharging your stones.

How to recognise genuine rock crystal

The market offers many materials that resemble rock crystal. A few pointers:

• Glass: no crystals, round bubbles or mould lines; it is softer (it can be scratched by quartz) and feels less cold. Objects made of "crystal" glassware (decanters, sparkling beads) are not rock crystal: they are glass, often lead glass.
• Synthetic quartz: it has the same composition as the natural form; it is not an imitation, but it should be disclosed.
• Dyed "crackle" quartz: a quartz heated and then dipped in a dye, recognisable by its coloured fissures. It is not colourless.
• "Aura" quartz: a natural crystal coated with a metallic layer that gives it rainbow reflections.
• Plastic: too light, warm to the touch, scratches with a fingernail.

For crystal balls: ours are made of optical glass and not of rock crystal, which is stated on their product pages; a large sphere of genuinely clear rock crystal is rare and expensive. See the guide to choosing and caring for your stones.

How to choose your rock crystal

• Transparency: inclusions (phantoms, veils, small fractures) are natural and give the piece its charm; a large crystal that is perfectly clear and flawless is more expensive, in relative terms.
• Shape: tumbled stone to start with, point for decoration, sphere for contemplation.
• Pairings: amethyst and citrine are two other quartzes; smoky quartz is a brown variety, often irradiated.

Frequently asked questions

Also read

The meanings mentioned belong to tradition and symbolism. They are neither promises of results nor medical advice. Back to Guide to stones.