Each page in this guide follows the same plan, so that you can compare stones easily. We start with what the stone is: its mineral family, its hardness on the Mohs scale (from 1, the softest, to 10, the hardest) and where it is found. Then comes its history, and the cultural traditions around it, which for some stones stretch back thousands of years. Next we say what crystal traditions associate with the stone, always attributed, and how people use it in practice, in meditation, in jewellery or simply on a shelf.

We take safety seriously. Some of these stones dissolve in water, some contain copper or other elements that should never be swallowed, some fade in sunlight and a few are fragile. Where that matters, it is written plainly on the page, and the care and safety guide gathers it all in one place.

We also say something about sourcing, because the gem trade includes mines with hard conditions for workers. Nothing here is advice to buy, and we do not link to shops.

If you are looking for the stone of a particular month, try the birthstones section or the birthstone finder. For stones linked to a zodiac sign, see crystals by zodiac sign.

The pages below run in a loose order, from the very familiar quartz family to less common stones.

Amethyst

Amethyst is purple quartz. Its geology, Greek name, place in royal and church jewellery, what crystal traditions associate with it, and care notes.

Rose Quartz

Rose quartz is pink quartz with no natural crystals. Geology, history from ancient beads to modern traditions, how people keep it, and care notes.

Clear Quartz

Clear quartz, or rock crystal, is silicon dioxide: geology, Greek and Japanese traditions, modern uses in watches, how people keep it, and care notes.

Citrine

Citrine is yellow to orange quartz, often made by heating amethyst. Its geology, history, what traditions say, and honest notes on natural and heated stones.

Black Tourmaline

Black tourmaline, or schorl, is a tourmaline with striated black crystals. Its geology, Dutch and Sri Lankan history, traditions, care and sourcing.

Selenite

Selenite is a crystal form of gypsum named for the Moon. Its geology, the giant Naica crystals, traditions, and why it must never be wetted or soaked.

Labradorite

Labradorite is a feldspar with a flash of colour called labradorescence. Its geology, Labrador and Finnish sources, Inuit stories, traditions, and care notes.

Moonstone

Moonstone is a feldspar with a soft, floating sheen called adularescence. Its geology, Sri Lankan and Swiss sources, Art Nouveau history, traditions and care.

Tiger's Eye

Tiger's eye is quartz with golden fibres that give a moving band of light called chatoyancy. Its geology, South African sources, traditions, care and sourcing.

Carnelian

Carnelian is orange-red chalcedony. Its geology, Indus and Roman history, Gujarat bead-making, what traditions associate with it, care and sourcing notes.

Lapis Lazuli

Lapis lazuli is a blue rock rich in lazurite. Its Afghan mines, Egyptian and Sumerian use, ultramarine pigment, what traditions say, care and sourcing.

Malachite

Malachite is a banded green copper carbonate. Its geology, Egyptian and Russian history, traditions, and safety: copper, dust, acids, water and elixirs.

Obsidian

Obsidian is natural volcanic glass, not a crystal. Geology, stone-age blades, Aztec mirrors and John Dee, traditions, and why edges need careful handling.

Jade

Jade is two minerals, nephrite and jadeite. Geology, Chinese yu, Maya and Maori traditions, what traditions associate with it, treated stones, and sourcing.

Turquoise

Turquoise is a blue-green copper aluminium phosphate. Geology, Persian, Egyptian, Tibetan and Native American traditions, care, stabilised stones and fakes.

Aventurine

Aventurine is quartz with glittering mica inclusions, usually green. Geology, the Murano glass story behind the name, traditions, care and common look-alikes.

Smoky Quartz

Smoky quartz is brown to grey quartz coloured by natural radiation. Geology, the Scottish cairngorm tradition, what crystal traditions say, care and sourcing.

Fluorite

Fluorite is calcium fluoride in purple, green and blue. Geology, Blue John from Derbyshire, the word fluorescence, traditions, and why it is delicate.

Hematite

Hematite is iron oxide that looks grey and metallic but streaks red. Geology, its use as red ochre and in Victorian jewellery, traditions, and magnetic fakes.

Pyrite

Pyrite is iron sulphide, known as fool's gold. Geology, fire-striking and Inca mirrors, traditions, and why pyrite should be kept dry and never put in water.

Garnet

Garnet is a family of silicate minerals, usually red. Geology, Anglo-Saxon and Bohemian history, the pomegranate name, traditions, care and sourcing.

Amazonite

Amazonite is a blue-green feldspar (microcline). Geology, the puzzle of its name, Ilmen Mountains and Colorado sources, traditions, care and fakes.

Rhodonite

Rhodonite is a pink manganese silicate with black veins. Geology, the Urals and Massachusetts, how it differs from rhodochrosite, traditions and care.

Sodalite

Sodalite is a blue sodium aluminium silicate with white veins. Geology, Canada, Brazil and Namibia, how it differs from lapis, traditions, care and dyes.