Types of Quartz
Clear, pink, smoky, purple, golden. One mineral, dozens of faces, and what makes each one different.
Quartz is the stone behind more of the crystal world than almost any other. Amethyst is quartz. So are citrine, rose quartz, smoky quartz and aventurine, and so, in a different form, are agate and jasper. The same simple chemistry shows up as pale pink, deep purple, golden yellow and glittering green, and the differences between them come down to what else was in the ground when each one formed.
This guide covers what quartz is, how the family divides, the main varieties and what sets them apart, and how to tell a natural colour from a treated one. Where a stone sold as quartz is not what it seems, we have said so.
What Quartz Is
Quartz is silicon dioxide, SiO2: one atom of silicon bonded to two of oxygen, repeated in a spiralling three-dimensional framework. It belongs to the silicate group described in our guide to mineral classes, and it crystallises in the trigonal system, which is why well-formed quartz grows as six-sided prisms topped with a pointed tip. If you would like the full picture, our guide to the seven crystal systems explains how that works.
It measures 7 on the Mohs scale, hard enough to scratch glass and steel and to last in everyday jewellery, and it is one of the most abundant minerals in the Earth's crust. That abundance is a large part of why it has been used so widely, from ancient carved beads to modern electronics.
The word "crystal" itself comes from the Greek for ice. The Roman writer Pliny the Elder believed clear quartz was water frozen so deeply that it could never thaw, an idea that shaped how people thought about the stone for centuries.
Two Families: Crystalline and Microcrystalline
Quartz divides into two broad groups, and the difference is the size of the crystals.
Macrocrystalline quartz has crystals large enough to see. This is the family people usually picture: clear quartz points, amethyst clusters, rose quartz, smoky quartz and citrine.
Microcrystalline quartz, also called chalcedony, is made of crystals so small they cannot be seen without a microscope. Agate, jasper, carnelian and onyx all belong here, which is why they look like solid, smooth stone rather than glassy crystal. We cover them in Types of Agate and Types of Jasper, so this guide concentrates on the first group and on varieties with inclusions.
Why Quartz Comes in So Many Colours
Pure quartz is colourless. Every colour in the family comes from something added to it, and there are three main causes.
Trace elements. A few atoms of iron, aluminium or titanium in the crystal can change its colour entirely. Iron is behind amethyst and citrine.
Natural radiation. Over millions of years, radiation from surrounding rock can alter the way certain impurities hold their electrons, producing colour. This is how smoky quartz gets its brown-grey tone from traces of aluminium.
Inclusions. Tiny crystals of other minerals trapped inside quartz create gold needles, green sparkle, dark threads or soft clouds. The quartz itself is still clear, and the colour belongs to what it is holding.
We look at what each colour is traditionally said to mean in Crystal Colour Meanings.
Quartz in Our Range
Several of the best-known quartz varieties are in our collection. As with all crystal meanings, the associations below are traditional and symbolic rather than scientific claims.
Also called rock crystal, this is quartz in its purest form: colourless and transparent. It is traditionally associated with clarity and with amplifying intention, and it has long been called a master stone. It is also the quartz that matters most to technology, because of a property we explore in Crystals and Energy Frequency.
Soft pink, usually cloudy rather than transparent, and rarely found as sharp crystals. It mostly forms in solid masses. The cause of its colour is still discussed, with trace elements and microscopic mineral fibres both proposed. Rose quartz is traditionally associated with love, gentleness and self-compassion.
Translucent grey to deep brown, coloured by natural radiation acting on traces of aluminium. It is traditionally associated with grounding and with letting go of what weighs on you.
Purple quartz, coloured by iron together with natural irradiation. Its colour can run from pale lilac to deep violet, and it is traditionally associated with calm and clear thinking. It is also February's birthstone.
Yellow to golden quartz, also coloured by iron, and traditionally associated with abundance, warmth and confidence. Natural citrine is less common than the market suggests, because a great deal of citrine on sale is amethyst or smoky quartz that has been heated. It is worth asking about any piece. Citrine is November's birthstone.
Quartz With Inclusions
In these varieties the quartz is the host, and the character comes from what is inside it.
Clear quartz threaded with fine golden needles of rutile, a titanium oxide mineral that grew inside the crystal as it formed. The needles can be sparse and delicate or dense enough to look like spun gold. It is traditionally associated with energy and illumination.
Shop golden rutilated quartz →
The same idea in darker tones: clear quartz holding black or very dark needles. Black needles are usually rutile, though similar-looking needles of tourmaline also occur, and the two are easy to confuse. It is traditionally associated with protection and grounding.
Green quartz with a shimmer, caused by tiny flakes of a chromium-bearing mica called fuchsite lying inside it. Light bouncing off the flakes gives a glittering effect known as aventurescence. Aventurine is traditionally associated with luck and opportunity, which is why it features in our good luck gifts guide.
Golden-brown bands that seem to move as you turn the stone, an effect called chatoyancy. Tiger's eye began as fibrous blue crocidolite, which was gradually replaced by quartz while its fine structure was preserved, and iron oxide added the gold and brown. It is traditionally associated with courage, focus and steadiness.
Other Quartz Varieties Worth Knowing
These are not in our range at the moment, but you will meet them elsewhere, so they are worth recognising.
White and cloudy rather than clear, because it is full of microscopic bubbles of fluid trapped as it formed. It is one of the most common forms of quartz, and a traditional symbol of calm.
Amethyst and citrine together in a single crystal, with purple and gold zones side by side. It is best known from Bolivia, and it happens when different parts of the same crystal formed under slightly different conditions.
A crystal with ghostly outlines of earlier growth stages visible inside it, like a smaller crystal inside a larger one. They are a record of pauses in growth, when something coated the crystal before it began growing again.
A larger quartz crystal covered in a fringe of smaller ones, giving a spiky, textured look. Those smaller crystals grew later on the surface of the first.
Naturally doubly terminated quartz crystals, with a point at each end, from Herkimer County in New York. They are not diamonds, but they are unusually clear and sharply faceted.
Clear quartz threaded with black tourmaline needles, sometimes sold under the name black rutilated quartz.
Natural, Treated and Synthetic Quartz
Quartz is also one of the most commonly treated stones on the market, and it is useful to know the main cases.
Heat treatment. Heating amethyst or smoky quartz can turn it yellow or orange, which is how a large share of commercial citrine is made. It is a long-established practice, and it is one reason natural citrine is less common than it appears.
Aura and coated quartz. Clear quartz can be coated with thin layers of metal vapour to produce rainbow, blue or gold surfaces, often sold as aura quartz or under names that suggest mystic colours. The colour sits on the surface and is not the stone's own.
Dyed quartz. Some bright pink, blue or green quartz is dyed.
Synthetic quartz. Large quantities of quartz are grown in laboratories, mainly for electronics, where its response to electrical current makes it valuable in watches and devices. Synthetic amethyst and citrine also exist.
None of this is unusual, but it is fair to ask any seller whether a piece is natural, heat-treated or coated.
Choosing a Quartz
With so much variety, it helps to start from what you want from a stone. For a clean, versatile choice, clear quartz suits almost anything. For something softer, rose quartz. For depth and grounding, smoky quartz or black rutilated quartz. For warmth, citrine or golden rutilated quartz. And for colour with sparkle, aventurine.
Every piece is natural, so no two will match exactly. That is part of the appeal, and a stone in your hand can feel quite different from the one in a photograph.
Not sure which stone suits you? Let us help you choose, or explore how crystals form in our science guides.
Find Your Stone The Science of CrystalsTypes of Quartz, Answered
What are the different types of quartz?
Quartz is divided into crystalline varieties with visible crystals, such as clear quartz, rose quartz, smoky quartz, amethyst and citrine, and microcrystalline varieties such as agate and jasper. Varieties with inclusions include rutilated quartz, aventurine and tiger's eye.
What is quartz made of?
Quartz is silicon dioxide, SiO2, in which each silicon atom is bonded to oxygen atoms in a repeating three-dimensional framework. Its colours come from trace elements, natural radiation or other minerals trapped inside it.
Is amethyst a type of quartz?
Yes. Amethyst is purple quartz, coloured by iron together with natural irradiation. Citrine, smoky quartz and rose quartz are also varieties of quartz.
Is quartz a crystal?
Yes. Quartz is a crystalline mineral that grows in the trigonal system, often as six-sided prisms with pointed tips. Microcrystalline types such as agate and jasper are made of crystals too small to see.
How hard is quartz?
Quartz measures 7 on the Mohs scale, which makes it hard enough to scratch glass and suitable for everyday jewellery.
Is citrine natural?
Natural citrine exists but is less common than the market suggests, because much of the citrine on sale is heat-treated amethyst or smoky quartz. It is reasonable to ask a seller which they are offering.
What is the difference between quartz and crystal?
Quartz is a specific mineral. "Crystal" is a broader word for any mineral with an ordered internal structure, and clear quartz is often simply called crystal or rock crystal.
Is quartz rare?
Quartz itself is one of the most common minerals in the Earth's crust. Some varieties are scarcer, such as natural citrine, ametrine and fine rutilated quartz.