Uses of Quartz: 10 Industries Ranked by Grade Needed

The main uses of quartz are in glass, electronics, optics, solar and semiconductor manufacturing, foundry casting, abrasives and jewellery. Clear rock crystal and its lab-grown copy, cultured quartz, are prized for two things: they turn pressure into a precise electric signal, and they let light pass with very little loss. The US Geological Survey reports that electronic applications account for most industrial use of quartz crystal, and that virtually all crystal used in electronics is now cultured rather than mined (USGS, Mineral Commodity Summaries 2026).

This guide ranks the important uses by the grade of quartz each one needs, from ordinary sand to flawless crystal. It adds dated USGS prices, a chart of US trade in piezoelectric quartz, and a calculator that shows how much value is added when rough cultured crystal is cut into usable blocks.

Uses of quartz at a glance

Quartz is silicon dioxide (SiO2). It is hard (7 on the Mohs scale), resists most chemicals and melts only at very high temperatures, which is why industry uses so much of it. But not all quartz is equal. A beach sand grain, a white vein, a clear six-sided crystal and a block grown in a factory end up in very different products. The table sorts the main uses by the form of quartz they need.

Only the top four rows need clear crystal or near-perfect purity. Most of the tonnage of quartz mined each year goes into the bottom rows: sand for glass, fracking, foundries and fillers. The value per tonne runs the other way.

Rock crystal, clear quartz and the forms industry buys

Pure quartz with no impurities is colourless and transparent. It is traditionally called rock crystal or clear quartz. The name comes from the ancient Greek word for ice, because some Greek writers thought the mineral was water frozen so hard it could never melt (International Gem Society). Colour comes from traces of other elements or from tiny inclusions: amethyst is purple, citrine yellow, smoky quartz brown and milky quartz white. Our guide to raw milky quartz covers the white vein form, how to identify it and what it is worth.

Industry and the USGS use a few terms that are worth knowing before reading prices:

• Lascas: natural quartz crystal or chunks of clear quartz, used as the raw feed to grow cultured crystal. Most lascas is mined in Brazil and Madagascar (USGS, 2026).
• Cultured quartz crystal: quartz grown in a pressure vessel from hot, silica-rich water. It copies the way crystals form in nature, but it can be grown in the size, shape and orientation a factory needs.
• As-grown and lumbered crystal: as-grown is the bar straight out of the vessel. Lumbered crystal has been sawn into a block with its faces cut to a known crystal direction, ready for slicing into wafers.
• High-purity quartz (HPQ): natural quartz ground and cleaned until it has less than 100 parts per million (ppm) of impurities, which means at least 99.99% SiO2. Ultra-high-purity grades have under 10 ppm (USGS, 2026).
• Silica sand: sand that is mostly quartz grains, sold by the tonne for glass, foundry and well work.

The USGS silica statistics page groups all of these with tripoli and special silica stone under one “silica” heading, which is why a search for quartz statistics often lands on sand figures.

Quartz in electronics: oscillators, filters and timers

This is the use that made clear quartz strategic. Quartz is piezoelectric: squeeze a correctly cut slice and it produces a small voltage; apply a voltage and it flexes. Jacques and Pierre Curie described the effect in 1880. Walter Cady built the first quartz crystal oscillator in 1921, and the first quartz clock followed in 1927 (quartz history summary).

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US trade in piezoelectric quartz

Unmounted piezoelectric quartz, metric tons per year

In an oscillator, a thin quartz wafer vibrates at one very steady frequency set by its size and cut. A circuit counts those vibrations to keep time or to hold a radio signal on its channel. Geology.com notes that billions of quartz crystals are used each year in oscillators for watches, clocks, radios, televisions, computers, phones, meters and GPS equipment. The USGS lists frequency controls, frequency filters and timers in communications equipment, computers and consumer goods as the main electronic uses (USGS, 2026).

The same principle runs a quartz crystal microbalance, a lab instrument that measures tiny changes in mass from the shift in a crystal’s frequency, and thin-film thickness monitors used when coating lenses and chips.

Why cultured rather than natural? Natural crystals often contain twinning (two crystal orientations grown together), inclusions and cracks that spoil the vibration. During the Second World War demand outran mine supply, and Brazil was the main source of suitable crystal. Laboratories in the United States and Europe then worked out how to grow quartz on a commercial scale, and by the 1950s hydrothermal growth was producing crystal at industrial scale. The Arkansas Geological Survey records that a federal buying station at Hot Springs tested more than 4,000 pounds of Arkansas oscillator quartz in 1943 alone, and that demand for mined Arkansas crystal fell once General Electric developed ways to grow quartz in the 1950s.

US trade in unmounted piezoelectric quartz shows how active this market still is. Imports rose from 69 tonnes in 2021 to 127 tonnes in 2024 before dropping to an estimated 70 tonnes in 2025, and exports peaked at 133 tonnes in 2023 (USGS, 2026). The USGS links the growth to demand for frequency-control oscillators and vibration sensors in aerospace, automotive and telecom equipment, and says 2025 trade was affected by tariff talks between the United States and China. Over 2021 to 2024, China (including Hong Kong) supplied 89% of US imports of cultured quartz crystal.

Cultured quartz crystal prices and what adds value

The USGS publishes a rounded price range for cultured crystal each year. As-grown cultured quartz was about US$200 per kilogram in 2023 to 2025, up from about US$100 in 2021 and 2022. Lumbered quartz, already sawn to shape, was about US$500 per kilogram in 2024 and 2025, up from US$300 in 2021 (USGS, Mineral Commodity Summaries 2026; 2025 figures are estimates). These are indicative values, not a quote: buyers pay by specification, and the price of a specific order depends on size, orientation, inclusion count and quantity.

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Cultured quartz crystal value

US$ per kilogram, USGS indicative values

The gap between the two prices is the value of cutting. Sawing loses material, so a buyer has to weigh the yield of usable lumbered blocks against the higher price per kilogram. The calculator below lets you test that with your own numbers.

Optical uses: lenses, windows, prisms and fused quartz

Clear quartz lets through visible light and much of the ultraviolet range, and it barely changes shape when it warms up. Optical-grade crystal is cut into specialised lenses, windows and filters for lasers, microscopes, telescopes, sensors and scientific instruments (Geology.com). Because quartz bends light slightly differently in different directions (it is birefringent), cut crystal is also used to make wave plates and polarising parts that control how light vibrates.

Many optical and lamp parts are not single crystals but fused quartz: high-purity quartz melted into a clear glass. Fused quartz keeps most of the purity and heat resistance of crystal and can be shaped into tubes, windows and vessels. High-temperature lamp tubing and specialty glass are two of the end uses the USGS lists for HPQ. Geology.com also notes that a few very pure sandstones, such as parts of the Oriskany Sandstone in West Virginia, have been selected for lenses in large telescopes.

High-purity quartz for solar and semiconductor crucibles

Every silicon wafer for a solar cell or computer chip starts as an ingot pulled from molten silicon. That silicon is melted in a crucible made of fused quartz, and the crucible must not add impurities to the melt. That is the job of HPQ, and it is the reason a small mining district in North Carolina matters to the global chip and solar trade.

In 2025 two companies produced HPQ in the United States, both around Spruce Pine, North Carolina. They mine pegmatite, a very coarse-grained granite-like rock, for feldspar and mica at the same time, then crush, wash, sort and chemically and thermally treat the quartz (USGS, 2026). The USGS estimated the United States was the leading HPQ producer, with other sources in Australia, Brazil, Canada, China and Russia among others. Read more about how these rocks form in our guide to pegmatite deposits.

The USGS price range for ground HPQ was US$500 to US$12,000 per tonne in 2025, down from a top of US$20,000 in 2023. The wide spread reflects the gap between lower grades and the purest crucible material. US sales were estimated at about 100,000 tonnes in 2025. The survey also notes that China’s Ministry of Natural Resources announced more than 35 million tonnes of HPQ reserves in Henan and Xinjiang in April 2025, with early tests of 99.995% to 99.998% purity, compared with more than 99.999% for Spruce Pine material (USGS, 2026). Demand for photovoltaic HPQ eased in 2024 and 2025, while semiconductors, electronics, fibre optics and specialty glass continued to support demand.

Quartz to silicon metal: alloys, silicones and chips

A larger tonnage of quartz is smelted. Quartzite or lump quartz is heated with carbon in an electric furnace to make silicon metal and ferrosilicon. In the United States the main buyers of silicon metal are aluminium alloy makers and the chemical industry, mostly for silicones. A small share is refined further into polysilicon, the ultra-pure silicon for solar cells and chips (USGS Silicon, 2026). Most ferrosilicon goes to steel and iron foundries.

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Silicon metal output by country

Thousand metric tons silicon content, selected countries, 2025 estimate (US withheld)

China dominates the world supply of silicon metal: an estimated 4,000 thousand tonnes of a world total of about 4,600 thousand tonnes in 2025, or roughly 87%. US production figures are withheld to protect company data, so the United States does not appear in the chart. The average US silicon metal price fell from 361.86 cents per pound in 2022 to an estimated 130 cents in 2025 (USGS, 2026).

Glass, foundry sand, abrasives and fillers

By weight, sand is the biggest use of quartz. In 2025 the United States sold or used an estimated 120 million tonnes of industrial sand and gravel worth about US$4.5 billion. About 81% went to hydraulic fracturing and well work and 7% to glassmaking. Fillers, foundry sand, filtration and recreational sand took another 7%, and chemicals, abrasives, silicon, ceramics and other minor uses about 1% (USGS Industrial Sand and Gravel, 2026). About 33% of glass containers are recycled as cullet, which reduces the sand needed.

• Glass: silica sand is the main ingredient of container glass, flat glass for windows and the glass in screens and solar panels.
• Foundry: sand moulds and cores hold their shape when molten iron, steel or aluminium is poured into them.
• Abrasives: quartz sand is used for sandblasting, sandpaper and scouring products, and dense microcrystalline quartz rock such as novaculite is cut into sharpening stones.
• Fillers and filtration: ground silica goes into paint, plastics, rubber and grout, and graded sand filters drinking water.

These bulk uses are covered in more depth, with a chart of US sand tonnage, in the milky quartz guide linked above. For rock crystal, they matter mainly as a contrast: a tonne of glass sand sells for tens of dollars, while a kilogram of lumbered cultured crystal is listed at hundreds.

Rock crystal in jewellery, carving and decoration

Clear quartz is common, so as a gem it has little value except in very large, flawless pieces. It is used for faceted stones, beads, carvings, decorative objects and lamps, and as the clear top of assembled triplet gems. Rock crystal can grow to enormous size. The Smithsonian Institution holds a flawless crystal ball 12.75 inches across and weighing 107 pounds, and faceted rock crystal gems of thousands of carats have been cut (International Gem Society, updated July 2025).

Rock crystal was also knapped into stone tools in prehistoric times, as flint and vein quartz were. Today the main market for natural clear crystal is specimens for collectors, museums and decoration. The Arkansas Geological Survey notes that demand from tourists, collectors and museums has raised the price of Arkansas crystals, with some fine clusters reportedly valued at tens of thousands of dollars. The Arkansas General Assembly made quartz crystal the official state mineral in 1976 (Act 128).

US natural and synthetic gemstone output, which includes quartz, was valued at about US$47 million in 2025, 30% lower than in 2024 (USGS Gemstones, 2026). Carvings, collections and jewellery were the main end uses.

Engineered quartz worktops and the silica dust risk

“Quartz” kitchen worktops are engineered stone: crushed quartz bound with resin and pigment. They are hard and resist stains, which made them popular, but cutting, grinding and polishing them can release large amounts of respirable crystalline silica. These particles are at least 100 times smaller than ordinary sand grains and can cause silicosis, lung cancer and other diseases. OSHA estimates about 2.3 million people in the United States are exposed to silica at work, and it has issued a joint hazard alert with NIOSH on countertop fabrication and installation (OSHA, crystalline silica).

The same risk applies to anyone crushing quartz rock, sawing crystal or blasting with sand. Wet cutting, dust extraction and a properly fitted respirator are the standard controls.

Where rock crystal and quartz feedstock come from

Quartz is found almost everywhere, but clear crystal and pure feedstock come from a few settings:

1. Hydrothermal veins: hot water moving through fractures deposits quartz, sometimes as open pockets of clear crystals. The Ouachita Mountains of Arkansas are the classic US example: the crystal belt runs about 30 to 40 miles wide and 170 miles from Little Rock into eastern Oklahoma, and most of its quartz is milky veins, with clear crystals in pockets (Arkansas Geological Survey).
2. Pegmatites: very coarse rocks that grow large crystals of quartz, feldspar and mica. Spruce Pine HPQ comes from pegmatite, and Brazil’s Minas Gerais is known for large rock crystal.
3. Cavities in sedimentary rock: the doubly pointed “Herkimer diamond” crystals of Herkimer County, New York, grow in pockets in dolostone.
4. Alpine fissures: open cracks in the Swiss Alps and other mountain belts are a historic source of large clear crystals.

The International Gem Society lists Hot Springs (Arkansas), Herkimer (New York), the Swiss Alps, Minas Gerais (Brazil), Japan, Madagascar, New South Wales (Australia), Myanmar and Canada among rock crystal localities. Brazil and Madagascar supply most lascas for growing cultured crystal (USGS, 2026). Lascas mining and processing in Arkansas, the last US source, ended in 1997 (USGS, 2026). For field tips on finding crystals yourself, see our post on finding quartz crystals, and for Australian rules see gemstone and gold fossicking in Queensland. Quartz veins are also the host rock for many gold deposits; our guide to types of ore deposits explains where they fit.

Environmental and land-use aspects of quartz mining

Most quartz is extracted by open pit or quarry, so the main impacts are land disturbance, dust, water use for washing and the waste rock and fine tailings left after sorting. HPQ adds chemical and thermal treatment steps that need careful handling of acids and wastewater. Crystal digging for specimens is small in scale but still needs the landowner’s or claim holder’s permission, and in some places a permit.

For larger projects, regulators expect baseline mapping of vegetation, drainage and existing disturbance before work starts and monitoring afterwards. Satellite imagery is one practical way to record that baseline and track changes in pit area, stockpiles and regrowth over time.

▶ A short clay-animation explainer of seven ways mining changes land, water and air. · 2:31

How to tell what a quartz deposit or crystal is good for

If you hold ground with quartz on it, or are offered quartz material, these checks decide which use it can reach:

1. Clarity and inclusions: clear crystal without cracks can go to specimen, carving or lascas markets; milky or cracked quartz cannot.
2. Size and shape: specimen value depends on well-formed terminations and clusters; lascas buyers look for clean chunks.
3. Chemistry: HPQ potential can only be judged by laboratory analysis of trace elements such as aluminium, titanium, iron, lithium and potassium, at parts-per-million level.
4. Tonnage and access: sand and quartzite need large, easily mined volumes close to road or rail, because the product is cheap per tonne.
5. Associated minerals: sulphides, iron staining or banding in a quartz vein can point to gold or other metals, which may be worth more than the quartz itself.

Before field work, satellite imagery can help screen a large licence for exposed veins, iron staining, clay alteration and access, so sampling goes to the most promising ground first. Farmonaut offers this kind of satellite mineral screening for licence owners and consultants.

▶ Explains in plain terms how remote sensing measures ground from a distance for mining. · 2:01

Frequently asked questions

What is quartz mostly used for?

By tonnage, quartz sand is used mostly for hydraulic fracturing, glassmaking, foundry moulds and fillers. By value, the key uses are cultured crystal for oscillators and optics, and high-purity quartz for the crucibles that make silicon wafers (USGS, 2026).

What is clear quartz crystal used for?

Clear quartz, or rock crystal, is used for carvings, beads, faceted stones, crystal balls and collector specimens. Clear natural chunks (lascas) are also feedstock for growing cultured crystal for electronics and optics.

Why is quartz used in watches and electronics?

Quartz is piezoelectric. A thin, precisely cut slice vibrates at a very steady frequency when voltage is applied, and a circuit counts the vibrations to keep time or control a radio frequency.

Is the quartz in electronics mined or made?

Almost all of it is made. The USGS reports that virtually all quartz crystal used for electronics is cultured crystal grown in pressure vessels, often from mined lascas or recycled rejected crystal.

What are the economic uses of quartz?

The main economic uses are glass, silicon metal and ferrosilicon, frac and foundry sand, fillers, abrasives, cultured crystal for electronics, high-purity quartz for solar and chip manufacturing, and gems and specimens.

How much is cultured quartz crystal worth?

The USGS gives indicative values of about US$200 per kilogram for as-grown cultured quartz and about US$500 per kilogram for lumbered quartz in 2025 (estimates). Actual prices depend on specification.

What is high-purity quartz used for?

High-purity quartz, with under 100 ppm impurities, is used for fused quartz crucibles for silicon ingots, fibre-optic cable, high-temperature lamp tubing, electronics and specialty glass.

Is clear quartz rare or valuable?

Clear quartz is common. Small pieces have little value; large, flawless crystals and fine clusters can be valuable to collectors and museums.

Is quartz used to make computer chips?

Yes, indirectly. Quartz is smelted into silicon metal, which is refined into polysilicon and grown into wafers in crucibles made of high-purity quartz.

Are quartz worktops safe?

The finished worktop is not the main concern. The risk is to workers who cut, grind and polish engineered stone, which can release respirable crystalline silica dust (OSHA).

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