Rare earth minerals
Monazite in the US: where it is mined and which projects depend on it
Monazite, (Ce,La,Y,Th)PO4, is a rare earth and thorium phosphate that the US recovers as a by-product of mining titanium and zirconium sands in Florida and Georgia and separates at White Mesa Mill in Utah. The USGS lists 35% to 71% rare earth oxide (typically 60% to 62%) and up to 20% thorium oxide.
4 tracked sites name it (Elk Creek, Bokan Mountain, Sheep Creek and White Mesa Mill), the USGS describes 8 more districts, and its 2002 database reports it at 71 sites in 16 states, 34 of them placers. Chemours supplies about 500 t/yr to Energy Fuels (company-reported).
Verified through Oct 1, 2026
- Operating US site
- 1White Mesa Mill, Utah
- Tracked sites naming it
- 4Of 14 on the map
- Thorium oxide in the mineral
- Up to 20%USGS, Table 3
- USGS 2002 sites naming it
- 71In 16 states
- Chemours monazite to Energy Fuels
- 500 t/yrCompany-reported
The definition
What is monazite?
Monazite is a rare earth and thorium phosphate mineral, (Ce,La,Y,Th)PO4, that collects as a heavy grain in sands and placers. The USGS says it typically holds 60% to 62% rare earth oxide and lists up to 20% thorium oxide, more than any other main rare earth mineral.
- Formula
- (Ce,La,Y,Th)PO4
- Oxide
- 35% to 71% rare earth oxide (typically 60% to 62%), 0 to 20% thorium oxide and 0 to 16% uranium oxide (USGS, Table 3 and text).
- Forms
- As a heavy, weathering-resistant grain that collects with ilmenite, magnetite, rutile and zircon in sands and placers (USGS), and in carbonatites, pegmatites and veins.
- Heavy part
- Sand concentrates are typically 1% to 3% dysprosium oxide and 0.3% to 1% terbium oxide (OSTI).
The comparison
Which US projects and districts depend on monazite?
4 tracked US sites name monazite and the USGS describes 8 more districts. White Mesa Mill is operating; Elk Creek is in development; Bokan Mountain and Sheep Creek are exploring. White Mesa Mill is the only site that processes it at commercial scale; the table sets out the rest, with USGS figures that are decades old.
| Project or district | Kind | Status | Deposit and minerals | Resource figures | Next step or latest activity |
|---|---|---|---|---|---|
| White Mesa MillUtah | Tracked project | Plant operating | Monazite separation and uranium mill | No resource estimate | Heavy rare earth expansion under construction since Jul 29, 2026; Tb and Dy circuits due end of 2027 |
| Elk CreekNebraska | Tracked project | Development | Carbonatite; niobium-scandium-titanium with magnet rare earthsThe OSTI review (Table A3) names bastnaesite and monazite. | 360 Mt with 1.04 Mt TREO at about 0.30% (OSTI review, 2026) | Construction start targeted Dec 2026, subject to EXIM financing |
| Bokan MountainAlaska | Tracked project | Exploration | Peralkaline complex; allanite, bastnaesite, monazite, xenotime; heavy-rare-earth rich | Ucore Apr 2026 estimate: 5.15 Mt at about 0.58% TREO (0.4% cut-off), about 29,900 t contained; totals summed from the published categories (OSTI review earlier listed 5.23 Mt at about 0.65%) | No mine schedule; Ucore focuses its near-term US effort on a Louisiana processing complex |
| Sheep CreekMontana | Tracked project | Exploration | Carbonatite; bastnaesite, allanite, monazite | No resource estimate | Forest Service review of a reduced plan filed Jun 12, 2026; decision estimated Jul 2027 |
| Wet MountainsColorado | USGS-described district | Company program | Thorium and rare earth veins, fracture zones and carbonatite dikes around three Cambrian alkaline complexes. Thorite, bastnaesite, synchysite, ancylite, monazite. | USGS 1988 (veins): reserves of 26,600 t of light and 17,700 t of heavy rare earths, plus probable potential of 66,500 t and 44,300 t, in veins averaging 0.21% light and 0.14% heavy rare earth oxides. Primary carbonatite dikes averaged 2.15% total oxide in 52 samples. | Feb 2, 2026. Magnum Mining and Exploration (ASX: MGU): Completed its acquisition of Wyoming Critical Minerals, owner of the Wet Mountains project (126 claims, 10.5 km2), after a binding term sheet on Dec 11, 2025. It cites historical assays of up to 7.99% total rare earths and plans sampling, trenching and drilling; no drilling had been done. |
| Idaho monazite placersIdaho | USGS-described district | None found | Stream placers with monazite, ilmenite, garnet and euxenite. Monazite (about 63% rare earth oxide), euxenite. | USGS 1980: about 9,130 t of thorium oxide reserves in the five main districts; the rare earth oxide would presumably be at least ten times that. | No activity found in the sources checked. |
| Hicks DomeIllinois | USGS-described district | Claims held | A dome 14.5 km across over an alkaline intrusion, with a thorium and rare earth breccia at depth. Monazite and florencite (tentative), with fluorspar. | No USGS estimate in 2010. One drill hole crossed mineralized breccia from 490 m to 897 m deep; eight core samples held 0.1% to 0.99% yttrium and up to 0.18% thorium oxide. The USGS says the depth may limit the resource. | Nov 18, 2025. CleanTech Vanadium Mining (TSXV: CTV): Closed the purchase of 37 fluorspar mineral-rights parcels (1,605 acres) around Hicks Dome for US$68,700, bringing its Illinois holdings to 2,846 acres. It says it is "intrigued" by possible rare earth discoveries nearby; no rare earth work is reported. |
| Pea RidgeMissouri | USGS-described district | Company program | Four rare earth breccia pipes cutting a magnetite and hematite iron orebody, with rare earths in apatite tailings. Monazite and xenotime in apatite. | A 1990 Bureau of Mines report: about 600,000 t of rare earth reserves at 12% oxide in the breccia pipes. The USGS notes the supporting data are missing. | Mar 16, 2026. Caldera Holdings (St. Louis): The owner says it plans to reprocess waste from the old iron mine for rare earths, develop phosphate for fertilizer and later return to underground mining; its chairman says partners are preparing to invest more than $1B. No permit or resource estimate was verified here. |
| El Porvenir (Hermit Mountain)New Mexico | USGS-described district | None found | Pegmatite dikes and quartz veins in Precambrian granite. Monazite. | No estimate. One quartz-rich sample held 546 ppm thorium, 582 ppm lanthanum and 1,160 ppm yttrium. | No activity found in the sources checked. |
| Petaca districtNew Mexico | USGS-described district | Claims held | Thorium and rare earth pegmatites in the Tusas Mountains, mined for mica from 1870 to 1944. Samarskite, monazite. | No estimate. One pegmatite held 10,332 ppm thorium and 3,117 ppm total rare earths and yttrium. | May 28, 2025. Almadex Minerals (TSXV: DEX): Reported that it had staked most of the historic Petaca district, a pegmatite dike complex with rare earth potential, as part of a regional program that mainly targets copper and gold. No rare earth work is reported. |
| Carolina monazite placersNorth Carolina, South Carolina | USGS-described district | None found | Stream placers with monazite in the headwater valleys of the Piedmont. Monazite (60% to 63% rare earth oxide). | USGS 1979: about 4,800 t of thorium oxide reserves in the 13 largest placers, implying roughly 53,000 t of rare earth oxide. | No activity found in the sources checked. |
| Florida and Georgia beach placersFlorida, Georgia | USGS-described district | Company program | Pleistocene and Pliocene beach sands with low-grade, persistent monazite; the main heavy mineral is ilmenite. Monazite, with ilmenite, rutile and zircon. | USGS 1980: reserves of about 198,000 t of rare earth oxide and 14,700 t of thorium oxide in 330,000 t of monazite. | Per the 2025 10-K. Chemours; Energy Fuels: Chemours supplies monazite from its Florida and Georgia mineral sand operations to Energy Fuels under an agreement signed on Dec 14, 2020 for a minimum of 2,500 tons a year; current supply is about 500 t/yr (company-reported). |
Nothing matches that search.
Tracked projects are the ones with a profile here; a project is listed when its deposit description names monazite or when the OSTI review (Table A3) does. USGS-described districts are the ones on the historic deposits page; their resource figures are decades-old USGS estimates made under no modern reporting code, never reserves.
Verified Oct 1, 2026 Every row links to a full profile where one exists.
Download the data: USGS 2002 sites by mineral (CSV)Projects by mineral (CSV)Minerals (CSV)
Where is monazite found in the US?
Monazite is recovered from heavy-mineral sands in Florida and Georgia and processed at White Mesa Mill in Utah. The USGS 2002 database reports it at 71 sites in 16 states: 34 placers, 13 phosphate mines in Idaho, 9 carbonatites and the rest pegmatites, veins and other rocks.
A mention of monazite at a site is a report that it occurs there, not a resource. For the Idaho phosphate mines the database's notes give about 0.1% rare earths in phosphate ore at Blackfoot Bridge and mark Smoky Canyon as a possible by-product producer.
| State | Sites | Sites, with links where this site covers them | USGS deposit types |
|---|---|---|---|
| Idaho | 25 | Bear Valley, Big Creek, Blackfoot Bridge, Caldwell Canyon, Champ, Conda and 19 more | 13 phosphorite, 6 placer, alluvial, 3 metamorphic, 2 other igneous (pegmatites and veins), 1 carbonatite |
| Alaska | 8 | Bokan Mountain (Ross-Adams), El Dorado Creek area, McGrath, Mount Prindle (Roy Creek), Port Clarence, Salmon Bay and 2 more | 4 placer, alluvial, 2 alkaline igneous, 1 carbonatite, 1 other igneous (pegmatites and veins) |
| Tennessee | 6 | Kerr-McGee deposit, Natchez Trace deposit, North Camden (Kerr-McGee deposit), Oak Grove (2 records), Silica Mine | 3 placer, shoreline, 2 placer, alluvial, 1 placer, paleoplacer |
| Florida | 5 | Boulougne, Green Cove Springs, Maxville, Trail Ridge (Highland Trail Ridge, Starke Trail Ridge), Vero Beach | 5 placer, shoreline |
| Wyoming | 5 | Bald Mountain, Bates Hole area, Bear Lodge Mountains (southern), Grass Creek area, Warm Spring Creek placers | 2 placer, alluvial, 2 placer, paleoplacer, 1 carbonatite |
| California | 4 | Mountain Pass, Music Valley, Pomona Tile Company, Soledad | 1 carbonatite, 1 metamorphic, 1 other igneous (pegmatites and veins), 1 placer, shoreline |
| Colorado | 3 | Gem Park, Iron Hill (Powderhorn, Cebolla Creek), Wet Mountains | 3 carbonatite |
| Georgia | 3 | Brunswick-Altamaha, Cumberland Island, Folkston | 3 placer, shoreline |
| New Mexico | 3 | Pajarito Mountain, Petaca District, Wind Mountain (see Cornudas Mtns) | 2 alkaline igneous, 1 other igneous (pegmatites and veins) |
| North Carolina | 2 | Carolina monazite belt, Marion | 2 placer, alluvial |
| South Carolina | 2 | Hilton Head Island, Horse Creek (Aiken County) | 1 placer, alluvial, 1 placer, shoreline |
| Arkansas | 1 | Magnet Cove | 1 carbonatite with residual enrichment |
| Missouri | 1 | Pea Ridge | 1 hydrothermal iron oxide |
| Montana | 1 | Ravalli County | 1 carbonatite |
| Nevada | 1 | Crescent Peak | 1 other igneous (pegmatites and veins) |
| Virginia | 1 | Old Hickory (Stony Creek) | 1 placer, shoreline |
The USGS Open-File Report 02-189 database (Orris and Grauch, 2002) lists the rare earth minerals reported at each site. A mention is a report that the mineral occurs there, not a resource or an ore, and a site counts once, under the first state it names. The download lists every record with its position where the USGS gives a usable one.
How much monazite does the US produce?
The USGS does not count monazite in its 51,000 t estimate for 2025, which excludes monazite concentrates, and it publishes no US monazite tonnage. Chemours supplies about 500 t/yr from Florida and Georgia to Energy Fuels (company-reported), under a three-year agreement signed on Dec 14, 2020 for a minimum of 2,500 tons a year.
Delivery shortfalls led to renegotiation, and Energy Fuels' larger planned sources are outside the US: Donald in Australia, Toliara in Madagascar and Bahia in Brazil. White Mesa's first run in 2024 turned 500 t of monazite into 38 t of NdPr product (company-reported).
- Source Chemours Heavy-mineral-sand operations in Florida and Georgia, including the Offerman plant in Georgia. About 500 t/yr today (company-reported).
- Processor White Mesa Mill Phase 1A takes up to 10,000 t/yr of monazite and states up to 1,000 t/yr of NdPr oxide (company-reported).
- Outside the US Donald, Toliara and Bahia Projects meant to supply up to 50,000 t/yr, ramping from 2026 to 2028 (company-reported).
What is the history of monazite in the US?
US monazite began with the Carolina placers in 1887, which made the US the world's first supplier of thorium from monazite, and returned in the 1950s when Idaho dredges recovered it for the Atomic Energy Commission. Tighter rules on radioactive minerals drove many monazite sources out of the market in the 1980s (USGS).
- 1887 to 1917 Carolina placersSmall sluice operations in North and South Carolina sell 4,973 t of monazite; beach sands in India and Brazil end the trade.
- 1950 to 1955 Idaho dredgesLong Valley dredges recover 6,430 t of monazite (269 t of thorium oxide) for the Atomic Energy Commission.
- 1978 Sand by-productTitanium Enterprises and Humphrey Mining recover monazite as a by-product in Florida and Georgia.
- 1980s Rules tightenThe USGS notes that tighter regulation of radioactive minerals drives many monazite sources out of the rare earth market.
- Dec 2020 Chemours agreementEnergy Fuels signs a three-year agreement for a minimum of 2,500 tons a year of monazite from Chemours in Georgia.
- 2021 White Mesa startsWhite Mesa Mill begins processing monazite, selling a mixed rare earth carbonate.
- 2024 Separation circuitThe circuit is commissioned: 500 t of monazite yields 38 t of NdPr product.
How is monazite processed?
Monazite is a heavy mineral, so sand operations concentrate it by gravity, magnetic and electrostatic separation to 50% to 60% or more TREO. White Mesa Mill cracks it with caustic soda, leaches it with hydrochloric acid, removes radium and recovers uranium before solvent extraction.
- Step 1 Concentrate Gravity, magnetic and electrostatic separation take monazite out of ilmenite, rutile and zircon sands (OSTI).
- Step 2 Crack and leach White Mesa cracks the monazite with caustic soda and leaches it with hydrochloric acid.
- Step 3 Purify Radium is precipitated as barium-radium sulfate and the uranium found is recovered as U3O8.
- Step 4 Separate Solvent extraction separates NdPr and other products, which are precipitated and calcined to oxide.
Is monazite radioactive?
Yes. The USGS lists up to 20% thorium oxide and up to 16% uranium oxide in monazite, more than any other main rare earth mineral, and says tighter rules on radioactive minerals drove many monazite sources out of the market in the 1980s.
White Mesa Mill processes monazite under Utah Radioactive Materials License UT1900479; Utah is an Agreement State (see NRC and Agreement State licensing). The USGS also notes a depletion allowance for domestic monazite of 22% on its thorium content and 14% on its rare earth content (MCS 2026).
| Mineral | Formula | Rare earth oxide | Thorium oxide | Uranium oxide |
|---|---|---|---|---|
| Bastnaesite | (Ce,La,Y)CO3F | 70% to 74% | 0 to 0.3% | 0.09% |
| Monazite | (Ce,La,Y,Th)PO4 | 35% to 71% | 0 to 20% | 0 to 16% |
| Xenotime | YPO4 | 52% to 67% | Not given | 0 to 5% |
| Allanite | Ca(Ce,La,Y,Ca)Al2(Fe2+,Fe3+)(SiO4)(Si2O7)O(OH) | 3% to 51% | 0 to 3% | Not given |
USGS Scientific Investigations Report 2010-5220, Table 3. The ranges describe the mineral worldwide, not any one US deposit or plant.
Does monazite contain heavy rare earths?
A little. Monazite concentrate from sands is typically 20% to 24% NdPr oxide, 1% to 3% dysprosium oxide and 0.3% to 1% terbium oxide, and White Mesa's blended feed is 22.4% NdPr, 1.1% dysprosium and 0.3% terbium (OSTI). White Mesa has made dysprosium and terbium oxide at pilot scale (company-reported).
Energy Fuels' heavy rare earth expansion is meant to add up to about 120 t/yr of dysprosium oxide and 20 t/yr of terbium oxide by the end of 2027 (company target); see US producers by element.
| Source | Mineral | Lanthanum and cerium | NdPr | Dysprosium | Terbium |
|---|---|---|---|---|---|
| Mountain Pass | Bastnaesite | 82.7% | 16.4% | 0.0% | 0.0% |
| Round Top | Yttrofluorite and xenotime | 32.4% | 11.8% | 5.7% | 0.9% |
| Monazite concentrate from sands, typical | Monazite | Not stated | 20% to 24% | 1% to 3% | 0.3% to 1% |
| White Mesa Mill blended monazite feed | Monazite | Not stated | 22.4% | 1.1% | 0.3% |
Figures are from the OSTI review (Table A2 and text); the columns do not sum to 100% because other rare earths are omitted.
Go deeper
How else can I browse US rare earth mines?
Each page has its own definition and comparison table. The profiles behind them carry the sources.
- 5 Bastnaesite in the US The mineral at Mountain Pass, the only US mine that produces rare earths as its main product.
- 2 Xenotime in the US The heavy-rare-earth and yttrium mineral, named at Round Top and Bokan Mountain.
- 4 Allanite in the US The host mineral at Halleck Creek and La Paz: huge tonnage, low grade.
- 5 Rare earth minerals Bastnaesite, monazite, xenotime, allanite and yttrofluorite: thorium, processing and the US projects that name each.
- 22 Historic and prospect deposits USGS-described districts without a profile, with the company activity found since 2024.
- ↑ Rare earth mines in the US The full directory with every status and role in one table.
- White Mesa MillThe only US site that processes monazite at commercial scale
- Energy FuelsThe buyer of US monazite
- NRC and Agreement State licensingThe radioactive materials rules for thorium-bearing ore
- Unconventional sourcesChemours monazite as a by-product of sands
- Bastnaesite in the USThe mineral at Mountain Pass
- Rare earth mineralsAll five minerals compared
- Historic and prospect depositsThe old monazite placers
- Rare earth in GeorgiaWhere the Offerman plant is
Questions about monazite in the US
Where is monazite found in the US?
In heavy-mineral sands in Florida and Georgia, which supply White Mesa Mill, in old placers in Idaho and the Carolinas, in carbonatites such as Bear Lodge and Iron Hill, and at 71 sites in the USGS 2002 database across 16 states.
Does the US mine monazite?
Not as a primary product. It is a by-product of titanium and zirconium sand mining, and the USGS says it is produced from heavy-mineral-sand concentrates in the southeast. Chemours supplies about 500 t/yr to Energy Fuels (company-reported).
Is monazite radioactive?
Yes. The USGS lists up to 20% thorium oxide and up to 16% uranium oxide in monazite. White Mesa Mill in Utah processes it under a state radioactive materials license.
How much rare earth oxide is in monazite?
The USGS lists 35% to 71% and says monazite typically holds 60% to 62%. Concentrates from sands are 50% to 60% or more TREO (OSTI).
What is the difference between monazite and bastnaesite?
Monazite is a thorium-bearing phosphate recovered from sands, with some dysprosium and terbium. bastnaesite is a low-thorium fluorocarbonate floated from carbonatite at Mountain Pass, with almost no heavy rare earths.
Who buys US monazite?
Energy Fuels, which separates it at White Mesa Mill. It signed a three-year agreement with Chemours on Dec 14, 2020 for a minimum of 2,500 tons a year from the Offerman plant in Georgia, and delivery shortfalls led to renegotiation.
Is monazite the same as xenotime?
No. Both are phosphates, but monazite is a light-rare-earth and thorium phosphate, (Ce,La,Y,Th)PO4, and xenotime is an yttrium phosphate, YPO4, richer in heavy rare earths.
Sources and verification
Each profile lists its sources, a confidence grade and a verification date. Order of authority: official records (SEC filings, agency documents), company documents and technical reports, research papers, then independent press. Syndicated copies and reference works are labeled and are never the only source for a number. Company-reported figures are labeled as such, and non-binding deals are labeled "letter of intent" or "conditional".
- USGS: The Principal Rare Earth Elements Deposits of the United States (Scientific Investigations Report 2010-5220) Official record
- USGS Mineral Commodity Summaries 2026 Official record
- OSTI review, Minerals Engineering 249 (Kashyap et al., 2026) Research paper
- USGS Open-File Report 02-189: rare earth element mines, deposits and occurrences (Orris and Grauch, 2002) Official record
- Energy Fuels 8-K: three-year supply agreement with Chemours for monazite (Dec 14, 2020) Official record
- Utah DEQ: Radioactive Materials License UT1900479, White Mesa Mill Official record
- Energy Fuels 10-Q for Q2 2026 (SEC) Official record
Tags show what kind of source each link is. How sources are ranked