Clear quartz

What it actually is

Silicon dioxide, trigonal, hardness 7, no cleavage. That last point matters: quartz does not split along a plane, so it survives being carried, dropped and worked, which is why so much of what survives archaeologically is made of it.

Clear quartz is quartz with nothing in it. No iron to make it violet, no titanium fibres to make it pink, no radiation damage to make it smoky. That absence is the whole character of the stone.

It has one genuinely unusual physical property. Quartz is piezoelectric: squeeze a crystal along the right axis and it produces a small voltage, and apply a voltage and it oscillates at a very stable frequency. That is what makes quartz watches and radio circuits work, and it is the real fact underneath a great many exaggerated modern claims.

The Greek word krystallos meant both ice and rock crystal, because the stone is cold to the touch and stays cold, and Pliny concluded it was ice frozen so hard it could not melt. That mistake gave English the word crystal for every mineral.

Where it comes from

Quartz crystallises late from silica-rich fluids and lines cavities, fills veins and finishes cooling granites, which means it occurs almost everywhere.

The great specimen sources are Brazil, particularly Minas Gerais, and Madagascar, with the Arkansas deposits in the United States supplying clear points in quantity. Alpine fissure quartz from Switzerland and Austria is prized by collectors for clarity and habit. Himalayan material from Nepal and India comes from high-altitude fissure deposits.

Herkimer diamonds are a locality name, not a diamond of any kind: doubly terminated quartz crystals that grew free in cavities in dolostone in New York State, so they have no attachment point.

Industrial quartz is grown hydrothermally in enormous quantity for electronics, since natural crystals cannot supply the demand.

What the traditions claimed

Because clear quartz holds no colour, it tended to be given the jobs that needed a neutral instrument rather than a specific virtue.

Scrying is the best documented. Renaissance manuals describe gazing into a translucent sphere or a polished stone under specified conditions of light and preparation. John Dee's shewstone in the British Museum is smoky quartz, and the transparent crystal ball of popular imagination is a later, largely theatrical form.

Rock crystal spheres were also used to concentrate sunlight and start fires, a use recorded in Rome and in Han China, sometimes for lighting sacred flames.

Egyptian craftsmen cut clear quartz into inlaid eyes for statues, where a transparent lens over white gives an unsettlingly lifelike gaze.

The modern claims, that clear quartz amplifies other stones and can be programmed with an intention, are twentieth-century and borrow their vocabulary from radio and computing. Neither has any support outside the tradition that produced them.

How it is worked with

This is the right first stone for anyone, precisely because it does not lean the exercise in any direction. Carry a tumbled piece for a month and notice what you actually reach for it for, rather than reading what you are supposed to feel.

In grids it is used as the centre or as the outer points, with the theme supplied by the surrounding stones. In meditation it is the standard object for simple attention practice, where the point is the returning rather than the stone.

Practically it is the most forgiving thing in the catalogue: hardness 7, no cleavage, chemically inert, safe in water, safe in sunlight, and cheap enough that losing one is not a disaster.

If you want to spend money on a crystal, spend it on something else. A large clear quartz point costs a great deal and does nothing a pebble does not.

Buying it honestly

Glass is the main substitution, and the tests are quick. Quartz conducts heat away from your skin and stays cool for several seconds; glass warms almost at once. Under a loupe, quartz shows angular veils, needles and fingerprint-like healed fractures, while glass shows round bubbles and swirls. A moulded glass point usually has a faint seam.

Aura quartz, in every metallic rainbow finish, is real quartz with a vapour-deposited metal film applied in a vacuum chamber, a technology from the 1980s. It is a manufactured surface, and any page describing its ancient meaning has invented one.

Synthetic quartz is grown industrially in vast quantity and occasionally reaches the decorative market. It is chemically identical.

Watch for invented names attached to ordinary quartz with a particular inclusion or growth habit; some describe real and interesting features, and many are marketing.