Quartz

Quartz (silicon dioxide) is one of the most common minerals on Earth, making up about 12 percent of the Earth's crust. It is found in almost every type of rock and forms some of the most familiar crystals: six-sided prisms ending in pointed tips. Quartz is hard, durable and widely available, and more gemstone varieties belong to the quartz family than to any other mineral.

Quartz varieties are usually divided into two groups. Crystalline (macrocrystalline) quartz forms visible crystals and includes rock crystal (clear quartz), amethyst (purple), citrine (yellow to orange), rose quartz (pink), smoky quartz (brown to black), prasiolite (green), ametrine (purple and yellow) and milky quartz. Quartz with inclusions includes rutilated quartz, tourmalinated quartz, aventurine, tiger's eye and cat's eye quartz. Microcrystalline (cryptocrystalline) quartz, or chalcedony, is made of crystals too small to see and includes agate, onyx, carnelian, chrysoprase, jasper and bloodstone.

The name probably comes from the old German "quarz". Clear rock crystal was once believed to be ice that had frozen so hard it could never melt, and the Greek word "krystallos", meaning ice, is the origin of the word crystal. Rock crystal has been carved into seals, vessels and crystal balls since ancient times.

Quartz is piezoelectric: it generates an electrical charge under pressure and vibrates at a precise rate in an electric field, which is why quartz crystals are used in watches, clocks, radios and electronics. Synthetic quartz is grown in large quantities for industry and jewellery, and glass is the most common quartz imitation; real quartz feels cooler to the touch and is harder.

Quartz at a glance

Caring for quartz

Quartz is hard (7 on the Mohs scale) and has no cleavage, so it is durable for everyday jewellery. Clean it with warm soapy water and a soft brush, then rinse and dry. Ultrasonic cleaning is usually safe for clear, untreated quartz, but avoid it for dyed, coated or included stones. Avoid sudden temperature changes. Some coloured quartz, such as amethyst, rose quartz and citrine, may fade in strong sunlight. Store separately from harder gems.

In folklore

The beliefs below are traditional folklore, included for interest. They are not scientifically proven, and nothing here is medical advice.

In ancient Greece and Rome, clear quartz was believed to be permanently frozen ice sent by the gods. Many cultures, including the ancient Celts, Australian Aboriginal peoples and Native Americans, used quartz crystals in ceremonies and healing, and crystal balls made from rock crystal have long been used for scrying (seeing the future). In Japan, quartz was thought to be the breath of a white dragon. Clear quartz is associated with all zodiac signs, and particularly with Aries and Leo.

Clear quartz is traditionally known as the "master healer" and is considered the most versatile crystal in healing traditions. Crystal healing lore holds that it amplifies energy and intention, brings clarity of mind and focus, and can be used to enhance the effects of other crystals. It is associated with all the chakras, especially the crown chakra. Each coloured variety of quartz is given its own meaning.

Related stones

Rock crystal, amethyst, citrine, ametrine, rose quartz, smoky quartz, prasiolite, milky quartz, rutilated quartz, tourmalinated quartz, aventurine, tiger's eye, hawk's eye, cat's eye quartz, strawberry quartz and the chalcedonies (agate, onyx, carnelian, chrysoprase, jasper, bloodstone). Imitations include glass and synthetic quartz.

For the technically minded

Shop quartz beads

← All gemstones in the guide