The most common volcanic rock on Earth

Basalt: where it forms, where it is quarried, and how America uses it

Basalt makes up most of the ocean floor, the great flood-basalt plateaus of the Pacific Northwest, the Hawaiian Islands, and the “traprock” ridges of the Northeast. In the United States it is crushed by the tens of millions of tons for roads, rail and concrete, spun into insulation, drawn into fiber, and ground into farm soil. This site explains each use and the exact rock qualities it demands.

Explore the 29 uses & specs Basalt in the USA
~6%of all U.S. crushed stone is traprock (basalt, diabase, gabbro) — roughly 85–90 million tons a year (USGS)
1.48 Gttotal U.S. crushed stone produced in 2025; ~72% goes to construction, mostly roads
>70%of Earth’s surface is underlain by basalt (the oceanic crust)
2.8–3.0specific gravity — denser than limestone or granite, a key advantage for ballast and riprap
Columnar basalt cliffs
Cooling joints split thick lava flows into the hexagonal columns basalt is famous for.
Basalt quarry with crushing plant
A working traprock quarry: the same face may feed road base, ballast, and landscape rock.
Flowing basaltic lava
Basalt begins as the runniest, hottest common lava on Earth.

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Geology

What is basalt?

Composition, how it forms, the difference between basalt, diabase, gabbro, scoria and “traprock,” and the physical properties that make it useful.

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World

Where basalt is found worldwide

From the Deccan and Siberian Traps to Iceland, Hawaii and the mid-ocean ridges — the largest basalt provinces on the planet.

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USA

Basalt in the United States

The Columbia River Basalt Group, Snake River Plain, Hawaii, the Midcontinent Rift, the Northeast traprock belt, and the Southwest volcanic fields — and which states quarry the most.

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Specs

29 uses & quality requirements

Landscape rock to asphalt friction aggregate to stone wool insulation: what tests each use runs and the numbers basalt must hit.

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Value

Little-known uses

Cast basalt liners, lunar-soil simulants, thermal batteries, radiation shielding, CO₂ mineralization, basalt fiber fire barriers and more.

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Value

Trace minerals in basalt

Native copper and silver, zeolites, agates, peridot, nickel-copper-PGE sulfides, vanadium-titanium magnetite, and other minerals that raise a basalt deposit’s value.

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Featured uses

High volume

Landscape Rock & Decorative Stone

Black and charcoal-grey ground cover, boulders, columns, and dry-creek stone for residential and commercial landscapes.

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High volume

Asphalt Pavement Friction (Skid-Resistant) Aggregate

Coarse aggregate in hot-mix asphalt surface courses where polish resistance and long-term skid resistance are specified.

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High volume

Stone Wool (Mineral Wool / Rock Wool) Insulation

Melted and spun into fibers for thermal, fire, and acoustic insulation in buildings, ships, and industry.

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High volume

Railroad Ballast

Large, angular, open-graded stone that locks rail ties in place and drains the trackbed.

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Specialty / high value per ton

Continuous Basalt Fiber & BFRP Rebar

Basalt melted and drawn into continuous filaments, then woven into fabric or pultruded into non-corroding composite rebar and bars.

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Medium volume

Enhanced Rock Weathering (Carbon Dioxide Removal)

Spreading crushed basalt on cropland so it reacts with CO₂ and rainwater, locking carbon into bicarbonate that eventually reaches the ocean.

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Basalt by the numbers

What U.S. crushed stone is made of Share of the 1.48 billion metric tons produced in 2025, by rock type
Limestone & dolomite Limestone & dolomite: 70% of U.S. crushed stone 70% Granite Granite: 14% of U.S. crushed stone 14% Traprock (basalt, diabase, gabbro) Traprock (basalt, diabase, gabbro): 6% of U.S. crushed stone 6% Miscellaneous stone Miscellaneous stone: 6% of U.S. crushed stone 6% Sandstone & quartzite Sandstone & quartzite: 3% of U.S. crushed stone 3% Marble, cinder, shell, slate & other Marble, cinder, shell, slate & other: 1% of U.S. crushed stone 1%
View as table
Rock typeShare of U.S. crushed stone
Limestone & dolomite70%
Granite14%
Traprock (basalt, diabase, gabbro)6%
Miscellaneous stone6%
Sandstone & quartzite3%
Marble, cinder, shell, slate & other1%

Source: USGS Mineral Industry Surveys, crushed stone, 2025 (via Rock Products, Aug 2026).

Where U.S. basalt is quarried Tile map — each state drawn the same size so the small Northeast traprock states are visible
  • Major traprock producer
  • Significant basalt / diabase
  • Minor basalt or consumer only
  • Little or no basalt
AK — Aleutian & interior basalt AK ME ME VT VT NH NH WA — Columbia River Basalt — ~half of state crushed stone WA ID — Snake River Plain & Columbia basalt ID MT — Stillwater Complex; Columbia basalt fringe MT ND ND MN — North Shore basalt & Duluth gabbro MN IL IL WI — Keweenawan basalt, roofing granules WI MI — Keweenaw basalt — native copper district MI NY — Palisades & Adirondack gabbro NY RI RI MA — Holyoke basalt / Westfield traprock MA OR — Columbia River & Cascade basalt — ~half of state crushed stone OR NV — Lunar Crater, Black Mountains fields NV WY WY SD SD IA IA IN IN OH OH PA — Gettysburg & Newark basin diabase PA NJ — Palisades & Watchung traprock — ~60% of state crushed stone NJ CT — Connecticut Valley traprock CT CA — Modoc Plateau, Clear Lake, Cima fields CA UT — Black Rock Desert & St. George fields UT CO — Table Mountain & Raton basalt CO NE NE MO MO KY KY WV WV VA — Culpeper basin diabase (Leesburg, Manassas) VA MD — Diabase & greenstone granules MD DE DE AZ — San Francisco & Springerville fields; lunar simulant AZ NM — Zuni-Bandera, Carrizozo flows NM KS KS AR AR TN TN NC — Deep River / Durham basin diabase NC SC SC OK OK LA LA MS MS AL AL GA GA HI — ~90% of crushed stone is basalt HI TX — Knippa traprock (Uvalde) hauled statewide TX FL FL

Categories from USGS traprock production by state and state geological survey quarry inventories.

The basalt value ladder Approximate U.S. value per ton by product, 2026 (logarithmic scale)
$10/ton$100/ton$1k/ton$10k/ton$100k/ton Road base / fill (at quarry) Road base / fill (at quarry): $12–$25 per ton Asphalt & concrete aggregate Asphalt & concrete aggregate: $18–$35 per ton Railroad ballast Railroad ballast: $20–$40 per ton Riprap / armor stone Riprap / armor stone: $25–$80 per ton Landscape rock (delivered) Landscape rock (delivered): $60–$200 per ton Agricultural rock dust (bagged) Agricultural rock dust (bagged): $80–$400 per ton Roofing granules (coated) Roofing granules (coated): $150–$400 per ton Columnar feature stone Columnar feature stone: $300–$1.5k per ton Cut pavers & tile Cut pavers & tile: $1.5k–$4k per ton Cast basalt liners Cast basalt liners: $2k–$6k per ton Continuous basalt fiber Continuous basalt fiber: $4k–$10k per ton Massage / spa stone sets Massage / spa stone sets: $15k–$60k per ton
View as table
ProductApprox. $/ton
Road base / fill (at quarry)$12 – $25
Asphalt & concrete aggregate$18 – $35
Railroad ballast$20 – $40
Riprap / armor stone$25 – $80
Landscape rock (delivered)$60 – $200
Agricultural rock dust (bagged)$80 – $400
Roofing granules (coated)$150 – $400
Columnar feature stone$300 – $1.5k
Cut pavers & tile$1.5k – $4k
Cast basalt liners$2k – $6k
Continuous basalt fiber$4k – $10k
Massage / spa stone sets$15k – $60k

Order-of-magnitude ranges from quarry price lists, landscape-supply retail, USGS unit values and fiber/cast-basalt trade pricing; local prices vary widely.

Why a site about basalt? Basalt is ordinary enough to be quarried in nearly every state that has it, yet the same rock can be worth $15 a ton as road base, $150 a ton as landscape rock, $2,000+ a ton as continuous fiber, and — where it carries native copper or gem-grade peridot — far more. Knowing which qualities each buyer tests for is what turns rock into revenue.