Quartz Family
Clear Quartz
Clear quartz, also called rock crystal, is silicon dioxide in its purest, most transparent form — no significant trace elements, no color centers, just SiO2 grown slowly enough to form large, optically clean crystals. It's one of the most common minerals in Earth's crust (quartz makes up roughly 12% of it by volume), but genuinely flawless, well-terminated clear crystals are still cut for jewelry and display because clean growth over a large size is uncommon even though the raw material is everywhere.
The geology — what Clear Quartz actually is
- Mineral class
- Silicate (quartz group, SiO2)
- Chemical formula
- SiO2 (near-pure, minimal trace elements)
- Crystal system
- Trigonal
- Mohs hardness
- 7
What causes the color: Colorless because it lacks the trace-element impurities (iron, aluminum, etc.) and irradiation history that produce color centers in amethyst, citrine, or smoky quartz — this is quartz in its chemically 'default' state.
How it forms: Forms in an extremely wide range of geological settings — hydrothermal veins, granite pegmatites, alpine-type fissures, and as a common accessory mineral in igneous and metamorphic rocks — because silica is abundant and quartz is stable across a huge range of temperatures and pressures. Well-formed hexagonal prisms with pointed terminations typically grow into open cavities where crystals aren't crowded by neighbors.
- Herkimer County, New York, USA (short, doubly-terminated 'Herkimer diamonds')
- Minas Gerais, Brazil (large clusters and points)
- Arkansas, USA (Ouachita Mountains — a major historical source)
- Swiss Alps (classic alpine-fissure specimens)
Treatments & imitations: Rarely treated since it's already colorless, though it's sometimes coated with a thin metallic film ('aura quartz,' e.g. titanium- or platinum-coated) to produce an iridescent rainbow surface — a deliberate, disclosed man-made coating, not a natural property. Cut clear quartz is sometimes substituted for genuine diamond or other colorless gems in costume jewelry due to its similar transparency.
Real vs. fake: Genuine natural clear quartz almost always contains at least some internal features under magnification — tiny fractures ('fingerprints'), rutile needles, or slight cloudiness — because perfectly inclusion-free crystals of any real size are unusual. Cut glass ('crystal' glassware) is heavier due to lead content, softer (scratches easily), and shows swirl marks or bubbles; genuine quartz will scratch glass, and glass won't scratch it.
The tradition — how people use Clear Quartz
Historical use: Clear quartz spheres and points have been used across many cultures for divination and ceremony — Roman and Chinese sources both describe quartz 'crystal balls,' and Indigenous Australian and North American traditions independently used clear quartz in ritual and healing practices, making it one of the most cross-culturally significant minerals in human history.
Metaphysical tradition: Modern crystal-healing tradition frequently calls clear quartz the 'master healer' or an amplifying stone, believed to intensify the properties of other crystals placed near it and to support mental clarity. It's traditionally paired with the crown chakra.
How to use it: Often placed alongside other crystals in the belief it amplifies their properties, used as a meditation focal point, or carried as a simple, all-purpose tumbled stone. Points are sometimes used in grid layouts (arranging several stones in a geometric pattern) in crystal-healing practice.
Cleansing & care: Extremely durable (Mohs 7) and safe to clean with water; unlike its colored quartz relatives, it has no color to fade in sunlight, so it's one of the few crystals that's genuinely safe to leave in a sunny window indefinitely from a material standpoint.
Frequently asked questions
Is clear quartz the same thing as glass?
No. Clear quartz is a crystalline mineral (SiO2) with a defined trigonal structure and Mohs hardness of 7; glass is amorphous (no crystal structure) and typically much softer, around Mohs 5.5. A genuine quartz point will scratch glass; glass won't scratch quartz.
What is aura quartz?
Aura quartz is natural clear quartz that's been coated with a thin layer of vaporized metal (commonly titanium or platinum) in a lab process, producing an iridescent rainbow surface sheen. It's a real, disclosed man-made treatment, not a naturally-occurring color.
Why does quartz work in watches and electronics?
Quartz is piezoelectric — applying an electric current makes it vibrate at an extremely precise, consistent frequency. That property (unrelated to any metaphysical use) is why 'quartz watches' use tiny synthetic quartz crystals to keep time.
Related crystals
Amethyst
Quartz Family
Amethyst is the purple variety of quartz, and the color you're looking at is a genuinely unusual optical effect: iron impurities trapped in the crystal lattice, altered by natural irradiation over geological time, absorb light in a way that produces violet rather than the yellow or clear you'd expect from plain silica. It's one of the few gemstones where color-causing chemistry, not rarity, is the whole story — amethyst is abundant, but the specific combination of iron content and irradiation dose that produces a deep, even purple is not, which is why fine material still commands a premium over pale or included specimens.
Selenite
Gypsum Family
Selenite is the clear-to-white, fibrous or bladed variety of gypsum — calcium sulfate dihydrate — and it's the single softest crystal commonly sold in the crystal trade: at Mohs 2, it's soft enough to scratch with a fingernail, which is both its most distinctive identifying feature and the reason it needs genuinely different care than the quartz-family stones most people are used to. Its name comes from Selene, the Greek moon goddess, for its pale, softly glowing luster.
Citrine
Quartz Family
Citrine is the yellow-to-orange variety of quartz, and here's the fact that surprises most buyers: genuinely natural citrine — colored that way by nature, never heated — is rare, while the vast majority of citrine sold commercially is amethyst or smoky quartz that's been heat-treated to shift its color. Both are real quartz with a real color change, but only one occurred without human intervention, and reputable sellers should be able to tell you which you're buying.
Smoky Quartz
Quartz Family
Smoky quartz gets its brown-to-black color through the same broad family of chemistry as amethyst's purple — trace-element impurities forming color centers under natural irradiation — but with aluminum standing in for amethyst's iron, producing smoke rather than violet. Much of the very dark, nearly opaque smoky quartz sold commercially today isn't purely a product of slow natural geology at all: clear quartz is routinely irradiated artificially to darken it, a disclosed industrial practice that speeds up a color change nature would otherwise take far longer to produce.
Where to buy Clear Quartz
We don't have an active affiliate program live yet, so instead of a placeholder link, here's the same buying guidance we'd give a friend.
Specialty mineral dealers & gem shows
The most reliable source for anything beyond common tumbled stones — sellers who specialize in minerals tend to disclose treatments and localities unprompted, because their repeat customers ask.
GIA/AGS-affiliated jewelers
For cut gemstones meant for jewelry (not raw specimens), a seller who can produce or reference an independent lab report (GIA, AGS) removes almost all of the real-vs-fake guesswork.
Marketplace sellers with a track record
Etsy and similar marketplaces host genuine small mineral dealers alongside mislabeled resin castings — check seller reviews specifically for photos of received items, not just star ratings.
Local rock & gem shops
Being able to handle a piece before buying lets you apply the weight and hardness checks described on each stone's own page — something no photo can substitute for.
Whichever seller you choose, ask directly whether the stone is natural or synthetic, and whether it's been treated (heated, dyed, irradiated) — a straightforward answer is the single best signal of a trustworthy seller, more useful than any star rating.
Some links on this page are affiliate links — if you buy through them, GemGlow may earn a small commission at no extra cost to you. We only link to sellers we'd genuinely recommend.
Sources and factual basis for the geology above: see our methodology.