Healing crystals: what does science say?

Scientifically speaking, no controlled study shows that stones cure illness, ease pain or change your mood. The calm some people feel when holding a crystal can be real, but in experiments real crystals and glass fakes produced the same sensations, so the effect comes from expectation rather than from the stone. Stones are beautiful, fascinating and culturally meaningful; they are still no substitute for treatment from a doctor, and some ways of using them are plainly harmful.

This article is not written to mock anyone who values crystals. Its aim is to explain honestly where the beliefs come from, what science has found and which practices are genuinely dangerous.

Where do the beliefs come from?

Giving stones protective or healing powers is as old as humanity. From ancient Egypt to Anatolia, stones were carried as amulets. Ancient and medieval writers produced lapidaries, books describing the physical properties and supposed virtues of stones. The Roman author Pliny the Elder devoted book 37 of his Natural History, written in the 1st century AD, to gems. A verse lapidary of 60 stones by Marbode, Bishop of Rennes (died 1123), became the most popular one in medieval Europe and was translated into eight languages.

Most of the “which crystal is good for what” lists you find online are much more recent. They spread with the New Age movement in the 1970s and 1980s. Katrina Raphaell’s Crystal Enlightenment (1985), for instance, was one of the popular books that matched stones to chakras and to particular complaints.

The beliefs also shift over time. The ancient Greeks thought amethyst prevented drunkenness; modern crystal books recommend the same stone for sleep and stress. The stone has not changed; the meaning people give it has.

The most asked-about stones: belief and science

Stone	Common belief (whose)	What science says
Amethyst	The ancient Greeks believed it prevented drunkenness; modern crystal healers say it calms and aids sleep.	A quartz coloured by traces of iron and natural radiation. No effect on sleep or anxiety has been shown.
Rose quartz	Crystal healers promote it as the “love stone”.	Ordinary quartz coloured by microscopic fibrous inclusions; no study shows an effect on emotions.
Tiger’s eye	Believed to guard against the evil eye; crystal healing says it gives confidence and courage.	The eye-like shimmer is a physical effect of light reflecting from parallel fibres.
Citrine	Called the “merchant’s stone” in crystal healing circles and said to bring abundance and money.	According to GIA, most citrine on the market is amethyst turned yellow by heating. There is no evidence it brings money.
Obsidian	The Aztecs believed obsidian mirrors could show the future; today it is said to “absorb negative energy”.	Rapidly cooled volcanic glass. “Absorbing energy” is not something that can be measured; broken edges are razor sharp.
Turquoise	Worn against the evil eye in Anatolia and the Middle East; medieval Europeans believed it protected riders from falls.	A porous mineral whose colour can change with sweat, oils and cosmetics; no protective power has been shown.
Onyx	In the Middle Ages and in Arab tradition it was thought to bring sorrow and quarrels.	A banded chalcedony. There is no basis for any effect on luck or feelings.
Agate	Marbode wrote that it made the wearer persuasive; in the Islamic world an agate ring is believed to protect from evil.	A chemically inert form of quartz; there is no scientific evidence of a protective effect.
Amber	Some sellers and parents believe teething necklaces ease babies’ pain.	A lab study found the beads release no active ingredient; the FDA warns of serious choking hazards.

Each stone’s own page gives the beliefs in more detail, with sources. For beliefs grouped by theme, see the Beliefs section.

What did the experiments show?

The best-known studies that directly tested crystal beliefs were carried out by psychologist Christopher French of Goldsmiths, University of London, and his students.

• The 1999 study: French and Lynn Williams asked 80 volunteers to relax for five minutes holding a crystal. Some crystals were genuine quartz; others were glass fakes that looked identical. Most volunteers reported at least one sensation, such as tingling or warmth. Those told in advance what they might feel reported more. Whether the crystal was real or fake made no difference at all.
• The 2001 study: The team ran a double-blind repeat with 80 new volunteers, with data collected by Hayley O’Donnell, and presented the results at the British Psychological Society’s conference in Glasgow. Again, real and fake crystals made no difference. The strength of the sensations rose with people’s belief in the paranormal and with their suggestibility.

To be fair, both studies were only presented at conferences and never published in a peer-reviewed journal. French pointed this out himself in 2021, noting that he knew of no other experimental work on the question. But no controlled study shows that crystals do have an effect either.

Magnetic jewellery tells a similar story: a 2007 analysis pooling nine placebo-controlled trials found that static magnets did not reduce pain significantly more than placebo.

There is also the physics. Quartz really is piezoelectric: squeeze a crystal and it produces a small voltage, which is how quartz watches keep time. But this only works when the crystal is under mechanical stress and connected to a circuit. A stone resting in your palm does not emit any energy that could affect the body.

Placebo: the feeling is real, the stone is not its source

The placebo effect is when an inactive treatment makes people feel genuinely better because they expect it to work. A quiet moment and a calming ritual, stone included, can truly help you relax. The problem starts when that feeling is mistaken for a cure.

Practices that can cause harm

“Crystal water” made with toxic stones

Some sources suggest soaking stones in water and drinking it as a crystal elixir. It has no known benefit, and with certain stones it is dangerous:

• Cinnabar contains mercury, galena lead and stibnite antimony. According to the World Health Organization, there is no known safe level of lead exposure.
• Realgar, which can look similar to cinnabar, contains arsenic.
• Malachite is a copper mineral that dissolves in acid; left in lemony or vinegary liquids, it releases copper.

These stones should never go in the mouth, be ground up or be put in drinks; wash your hands after handling them.

Radioactive “negative ion” jewellery

On 16 December 2021 the Dutch Authority for Nuclear Safety and Radiation Protection (ANVS) issued a warning. All ten “negative ion” products tested by RIVM (sleep masks, necklaces, bracelets and an “anti-5G” pendant) emitted ionising radiation and contained more radioactive material than the law allows. The measured dose was low, but because long-term harm from continuous wear could not be ruled out, ANVS told owners to stop wearing them and to store them away safely.

Amber teething necklaces for babies

The U.S. Food and Drug Administration (FDA) has received reports of choking, strangulation and death in babies linked to teething jewellery such as amber necklaces. And a 2019 laboratory study showed that the beads do not release succinic acid in amounts that could be absorbed through the skin.

Delaying treatment

The greatest danger is often not the stone but putting off a treatment that works. A US study published in 2018 compared 280 patients who chose only alternative methods for a curable cancer with similar patients who had standard treatment; the first group had about a 2.5 times higher risk of death. The study did not look at crystals specifically, but it shows the cost of abandoning treatment for a “natural” approach.

Looking at stones with respect

Loving a stone, giving it meaning, treating your grandmother’s turquoise ring as a lucky charm: all of this is human and valuable. Just keep one line clear: cultural meaning is one thing, health information is another. Wear a stone if it makes you happy; if you are ill, see a doctor.

If you wonder whether the stone you bought is really what the seller claimed, read our guide to fake gemstones; for what “precious” actually means, see what is a gemstone.