Rare earth minerals
Allanite in the US: where it is mined and which projects depend on it
Allanite is a rare earth silicate of the epidote group, and it is the host mineral at Halleck Creek in Wyoming, the largest US deposit by contained oxide, and at La Paz in Arizona. The USGS calls it common in igneous rocks but rarely concentrated enough to be an ore, and no US site produces from it.
4 tracked projects name it (Halleck Creek, Bokan Mountain, Sheep Creek and La Paz), the USGS describes 2 more districts, and its 2002 database reports it at 17 sites in 8 states. Halleck Creek is about 0.33% TREO and La Paz about 0.04%, so both rest on tonnage, and OSTI says production from allanite needs significant technology development.
Verified through Oct 1, 2026
- US sites producing from it
- 0Halleck Creek is in development
- Tracked projects naming it
- 4Of 14 on the map
- Rare earth oxide in the mineral
- 3% to 51%USGS, Table 3
- USGS 2002 sites naming it
- 17In 8 states
- TREO contained at Halleck Creek
- 8.7 MtOSTI review, 2026
The definition
What is allanite?
Allanite is a rare earth silicate mineral of the epidote group that carries cerium, lanthanum and yttrium. It is 3% to 51% rare earth oxide with 0 to 3% thorium oxide, and the USGS says it is one of the more common rare earth minerals in igneous rocks.
- Formula
- Ca(Ce,La,Y,Ca)Al2(Fe2+,Fe3+)(SiO4)(Si2O7)O(OH)
- Oxide
- 3% to 51% rare earth oxide and 0 to 3% thorium oxide; the USGS gives no uranium figure (Table 3).
- Forms
- Usually as an accessory mineral in igneous rocks such as granites, syenites and diorites and their pegmatites; it is one of the more common rare earth minerals in igneous rocks but rarely concentrated enough to be an ore (USGS).
- Grains
- Tabular and usually black, with a conchoidal fracture; commonly metamict, meaning the radioactive decay of thorium has destroyed the crystal structure (USGS).
The comparison
Which US projects and districts depend on allanite?
4 tracked US projects name allanite and the USGS describes 2 more districts. Halleck Creek is in development; Bokan Mountain, Sheep Creek and La Paz are exploring. The table sets out each one's deposit, resource figures and next step; filter by kind or state.
| Project or district | Kind | Status | Deposit and minerals | Resource figures | Next step or latest activity |
|---|---|---|---|---|---|
| Halleck CreekWyoming | Tracked project | Development | A-type granite; allanite | JORC 2.63 billion tonnes at 3,292 ppm TREO; about 8.7 Mt TREO (OSTI review, 2026) | Pre-feasibility study targeted Q3 2026; permit-to-mine filing late 2026 |
| 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 |
| La PazArizona | Tracked project | Exploration | Allanite-bearing; low grade | JORC 2012 (Aug 2021): 170.6 Mt at 391 ppm TREE (35.2 Mt indicated, 135.4 Mt inferred); contained TREE computed from tonnage and grade | Historic-data and metals-potential review continues through 2026 |
| 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 |
| Capitan MountainsNew Mexico | USGS-described district | None found | Twelve breccia veins of alaskite fragments cemented by quartz. Allanite (thorium), fluorite. | No estimate. 17 samples held up to 1.12% thorium; one select sample held 2,500 ppm lanthanum, 4,350 ppm cerium and 330 ppm yttrium. | No activity found in the sources checked. |
| Gold Hill and White SignalNew Mexico | USGS-described district | None found | Pods and lenses of rare earth and thorium minerals in pegmatites in the Burro Mountain granite. Euxenite, allanite, samarskite. | No estimate. Rare earth concentrations were not published; thorium reaches 0.72%. | No activity found in the sources checked. |
Nothing matches that search.
Tracked projects are the ones with a profile here; a project is listed when its deposit description names allanite. 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 allanite found in the US?
Allanite is the host mineral at Halleck Creek in Wyoming and La Paz in Arizona, and is named at Sheep Creek in Montana and Bokan Mountain in Alaska. The USGS 2002 database reports it at 17 sites in 8 states, across pegmatites, alkaline rocks, carbonatites, metamorphic rocks and placers.
A mention of allanite at a site is a report that it occurs there, not a resource; the USGS says it is rarely concentrated enough to be an ore.
| State | Sites | Sites, with links where this site covers them | USGS deposit types |
|---|---|---|---|
| Idaho | 6 | Chamberlin District, Hall Mountain Group, Indian Creek District, Lemhi Pass, North Fork area, Ramey Meadows | 2 metamorphic, 2 placer, alluvial, 1 carbonatite, 1 other igneous (pegmatites and veins) |
| Alaska | 3 | Bokan Mountain (Ross-Adams), Mount Prindle (Roy Creek), Ruby Meadows | 2 alkaline igneous, 1 placer, alluvial |
| California | 2 | Mountain Pass, Pomona Tile Company | 1 carbonatite, 1 other igneous (pegmatites and veins) |
| Wyoming | 2 | Laramie Anorthosite Complex, Tie Siding | 1 alkaline igneous, 1 other igneous (pegmatites and veins) |
| Missouri | 1 | Pea Ridge | 1 hydrothermal iron oxide |
| Montana | 1 | Ravalli County | 1 carbonatite |
| Texas | 1 | Llano County (Williams Mine, others) | 1 other igneous (pegmatites and veins) |
| Virginia | 1 | Little Friar Mountain (Massie) | 1 other igneous (pegmatites and veins) |
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.
Which US projects depend on allanite?
Halleck Creek holds a JORC resource of 2.63 billion tonnes at 3,292 ppm TREO, about 8.7 Mt contained, and La Paz holds 170.6 Mt at 391 ppm TREE. Both are large and lean next to the carbonatite projects, so their cases rest on tonnage, by-products and processing.
La Paz's company-reported scandium oxide content is about 4.4 million kg in the resource. Its grade is TREE, total rare earth elements, not oxide; in Mar 2026 the company hired a consultancy to review the property for gold, silver, copper and manganese as well.
- 5.98
- 3.05
- 0.33
- 0.3
- 0.04
Why is allanite hard to process?
Allanite has a complex mineralogy and the rare earths are present at low concentrations, so OSTI says production from it poses economic challenges and needs significant technology development. Halleck Creek's scoping flowsheet would not be viable if the mine sold only a concentrate, so its economics depend on further processing.
OSTI describes Halleck Creek's proposed flowsheet as very similar to Mountain Pass's: a beneficiated concentrate is calcined to convert Ce3+ to Ce4+, then leached in sulfuric acid. The pre-feasibility study was scheduled for Q3 2026 and the sources checked show no release.
- Step 1 Concentrate Halleck Creek plans dense media and wet magnetic separation to about 3.5% TREO, against about 60% from bastnaesite flotation.
- Step 2 Calcine and leach The concentrate is calcined and leached in sulfuric acid (OSTI), then separated by solvent extraction like other US projects.
- The economics A scoping study Phase 1 is 3 Mt/yr over 20 years with an after-tax NPV of $558M at 10% (company scoping study). A scoping study is an early-stage estimate.
Is allanite radioactive?
Somewhat. The USGS lists 0 to 3% thorium oxide in allanite and says its grains are commonly damaged by the radioactive decay of thorium. La Paz is reported to be low in thorium and uranium (company-reported); neither claim is a measurement from a plant.
See NRC and Agreement State licensing for when thorium- or uranium-bearing ore needs a radioactive materials license.
| 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.
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.
- 4 Monazite in the US The by-product of titanium and zirconium sand mining that feeds White Mesa Mill.
- 2 Xenotime in the US The heavy-rare-earth and yttrium mineral, named at Round Top and Bokan Mountain.
- 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.
- Halleck CreekThe largest US deposit by contained oxide
- La PazLow-grade allanite in Arizona, with by-product scandium
- American Rare EarthsThe owner of both allanite projects
- Bastnaesite in the USThe high-grade carbonatite mineral
- Rare earth mineralsAll five minerals compared
- How to read resource estimatesWhy 0.33% TREO is large but lean
- Types of US rare earth depositsGranite, carbonatite, clay and sand deposits
- Historic and prospect depositsThe USGS allanite districts in New Mexico
Questions about allanite in the US
What is allanite?
A rare earth silicate of the epidote group, Ca(Ce,La,Y,Ca)Al2(Fe2+,Fe3+)(SiO4)(Si2O7)O(OH), that carries cerium, lanthanum and yttrium. It is 3% to 51% rare earth oxide and common in igneous rocks (USGS).
Is allanite a rare earth ore?
Rarely. The USGS says allanite is one of the more common rare earth minerals in igneous rocks but is rarely concentrated enough to be an ore, and OSTI says production from it needs significant technology development.
What is the biggest allanite project in the US?
Halleck Creek in Wyoming: a JORC resource of 2.63 billion tonnes at 3,292 ppm TREO, about 8.7 Mt contained, the largest US deposit by contained oxide (OSTI). Its grade is about 0.33% TREO.
Is allanite radioactive?
Somewhat. The USGS lists 0 to 3% thorium oxide and says allanite grains are commonly metamict, damaged by thorium decay. La Paz is reported to be low in thorium and uranium (company-reported).
Does La Paz produce rare earths?
No. La Paz in Arizona is an exploration project with a 2021 JORC resource of 170.6 Mt at 391 ppm TREE and no economic study. In Mar 2026 its owner, American Rare Earths, hired a consultancy to review it for gold, silver, copper and manganese as well.
What is the difference between allanite and bastnaesite?
Allanite is a silicate found at low grades in granite and similar rocks, and needs technology development. bastnaesite is a fluorocarbonate found at high grades in carbonatite, and is proven at commercial scale at Mountain Pass.
Why is allanite low grade?
It is dispersed through a very large volume of rock: Halleck Creek is about 0.33% TREO and La Paz about 0.04%, against 5.98% at Mountain Pass. The projects' value rests on tonnage, heavy rare earths or by-products such as scandium.
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
- Mining Weekly: Halleck Creek rare earths project update (Apr 2026) Independent press
- Stockhead: La Paz resource upgraded (Aug 2021 JORC estimate) Independent press
- American Rare Earths: exploration update and 2026 to 2027 field programs (Jun 18, 2026) Syndicated copy
Tags show what kind of source each link is. How sources are ranked