Is Wavellite Radioactive?
Is wavellite radioactive? Not as a species: this secondary phosphate mineral has no uranium in formula or analysis. A specimen can hold trace uranyl ions.
No, not as a species. Wavellite, Al3(PO4)2(OH)3(H2O)5, contains no uranium or thorium; its Handbook sheet (hardness 3.5 to 4, density 2.36) prints no radioactivity and its analysis no uranium. But it forms in phosphate deposits, and USGS work in Florida found it in a zone that generally has the highest uranium; one Arkansas specimen’s glow is credited to trace uranyl.
In short
- Level 1, the formula: no. The September 2026 IMA-CNMNC Master List writes wavellite Al3(PO4)2(OH)3(H2O)5, status A, 1971 s.p., United Kingdom; the Handbook of Mineralogy writes Al3(PO4)2(OH,F)3·5H2O. A script over the formulas finds aluminium, phosphorus, oxygen, hydrogen and, on the Handbook, fluorine: no uranium, no thorium. autunite has two uranium atoms per formula.
- Level 2, the sheet: silent. The wavellite sheet has no “Radioactive” line, and its one analysis, from Clonmel, Ireland, reports P2O5, Al2O3, Fe2O3, F and H2O, totalling 99.55%. The same search finds “Radioactive” on the autunite and uraninite sheets, so the miss is real. Silence is not a measurement: the analysis did not look for uranium.
- Level 3, the setting: sometimes. The sheet places wavellite in low-grade metamorphic rocks and phosphate deposits. USGS Bulletin 1046-K says weathering in Florida’s land-pebble district changed fluorapatite to wavellite and crandallite, forming an aluminum phosphate zone marked by the highest uranium content on gamma-ray logs. That is the rock, not the species.
- One specimen, attributed. The Fluorescent Mineral Society’s entry 129 describes yellow wavellite from Mena, Polk Co., Arkansas, and attributes its green fluorescence to trace amounts of the uranyl ion. The same entry says Arkansas wavellite is typically green and non-fluorescent. One specimen is a specimen.
- The verdict. Wavellite is not a radioactive mineral; a given piece may carry trace uranium from where it grew, and only a measurement of that piece says so. What to do about any mineral that might be radioactive is routed to is my mineral radioactive; nothing here is advice.
| Level | Question | Wavellite | Autunite (control) | Source |
|---|---|---|---|---|
| 1. Formula | U or Th in the IMA formula? | No: Al3(PO4)2(OH)3(H2O)5 | Yes: Ca(UO2)2(PO4)2(H2O)11 | IMA list, September 2026 |
| 1. Formula | Uranium by mass (worked) | 0% | 49.17% | Standard atomic weights |
| 1. Formula | The fluorine analogue | Fluorwavellite, Al3(PO4)2(OH)2F(H2O)5, A, 2015-077, USA: no U or Th | — | IMA list |
| 2. Sheet | “Radioactive” printed? | No | Yes (uraninite sheet also yes) | Handbook of Mineralogy |
| 2. Sheet | Uranium oxide in the analysis? | None reported (Clonmel: P2O5, Al2O3, Fe2O3, F, H2O; total 99.55) | UO3 60.84 (Autun) | Handbook of Mineralogy |
| 3. Setting | Formed in uranium-bearing rock? | Can be: Florida aluminum phosphate zone, highest uranium on gamma-ray logs | Derived from primary uranium-bearing minerals | USGS Bulletin 1046-K; autunite sheet |
| 3. Setting | Which phosphate holds the uranium? | Not stated for wavellite; millisite “probably also a significant host” | Uranium is in the formula | Owens and others (1960) |
| 3. Specimen | A wavellite with uranium recorded | Yellow wavellite, Mena, Arkansas: green glow credited to trace uranyl | — | FMDB 129 |
Does wavellite contain uranium? The formula and the sheet
Wavellite’s formula has no uranium or thorium, on either list. The September 2026 IMA list writes Al3(PO4)2(OH)3(H2O)5; a script that splits the formula into element symbols returns Al, H, O and P. The Handbook of Mineralogy wavellite sheet writes Al3(PO4)2(OH,F)3·5H2O, adding fluorine. The IMA list also holds fluorwavellite, Al3(PO4)2(OH)2F(H2O)5, status A, 2015-077, USA, worked at 4.59% fluorine, and no uranium either. For comparison the autunite row, Ca(UO2)2(PO4)2(H2O)11, carries two uranium atoms and is 49.17% uranium by mass.
The sheet is silent, and the controls show the search works. The wavellite sheet’s physical properties run cleavage, fracture, tenacity, hardness 3.5 to 4 and density 2.36 measured, 2.37 calculated, and stop: no “Radioactive”. The same case-insensitive search finds it on the autunite sheet (“Dehydrates in air. Radioactive.”) and on the uraninite sheet. The sheet’s analysis, from Clonmel, Co. Tipperary, Ireland, reads P2O5 33.40, Al2O3 37.44, Fe2O3 0.64, F 2.79, H2O 26.45, less 1.17 for −O = F2, total 99.55, with no UO3, U3O8 or ThO2. Its fluorine is worked on the wavellite page; this page does not repeat it.
Documented failure: what silence proves. An analysis reports what was analysed for. Clonmel’s leaves 0.45% unaccounted, but that is not an upper limit on uranium, only the gap in the one analysis the sheet reproduces. So the sheet tells you the species carries no uranium; it cannot tell you a specimen carries none.
Why would a wavellite be radioactive? The phosphate setting
Because of the rock it grew in, not the mineral it is. The wavellite sheet calls it a secondary mineral in low-grade metamorphic rocks and phosphate deposits, rare in hydrothermal veins, with crandallite and variscite. USGS Bulletin 1046-K (Cathcart and McGreevy, 1959), a uranium report done for the U.S. Atomic Energy Commission, says that after deposition of the Bone Valley formation, weathering changed fluorapatite to wavellite and crandallite (pseudo-wavellite), forming the aluminum phosphate zone. It describes that zone as strongly altered by acid ground waters and characterised by aluminum phosphate minerals, kaolinite and, generally, the highest uranium content as indicated by the high peaks on the gamma-ray logs.
Where the uranium sits is a separate question. Owens, Altschuler and Berman (1960), American Mineralogist 45, 547 studied the same uraniferous aluminum phosphate zone and found millisite as a major constituent with crandallite and wavellite. They call millisite, like crandallite, an important intermediate phase in lateritically altered phosphorites and “probably also a significant host for uranium in such deposits”. Neither source assigns the uranium to wavellite, and this page does not either. Trace uranium in apatite and phosphate pebbles, from USGS data, is on is apatite radioactive.
How is wavellite formed? That is the other question people type, and the same two sources answer it: as a secondary mineral, here by weathering of a phosphate deposit that altered fluorapatite. The sheet’s localities, from High Down quarry in Devon to Mt. Ida in Arkansas, are on the species page.
Is my wavellite radioactive? One specimen on record
One fetched record ties a wavellite specimen to uranium, and it does so through fluorescence. The Fluorescent Mineral Society’s database entry 129 (Michael Crawford, 16 June 2025) describes a vug of yellow botryoidal wavellite from Mena, Polk Co., Arkansas. It says Arkansas wavellite typically has a green colour and lacks fluorescence, that the yellow variant often fluoresces green, and that the green fluorescence is activated by trace amounts of the uranyl ion; it compares the emission spectrum with autunite’s. The entry also reports Geiger-counter readings; count rates are outside this page.
What that does and does not show. It is the contributor’s attribution for one specimen, reported here as theirs. It does not make yellow wavellite radioactive as a rule, and green under UV is not a radioactivity test; the other glows on record, and why a database of glowing pieces is not a rate, are on is wavellite fluorescent, whose specimen ledger this page does not repeat.
The decision rule. Species: not radioactive, on its formula and its sheet. Specimen: unknown until measured, and a detector reading tells you about that piece and its matrix, not about wavellite. What to do about any mineral that might be radioactive, and whether wavellite is toxic, are hazard questions routed to is my mineral radioactive and toxic minerals in a collection; nothing here is advice. More such questions are in the collecting guides. Nothing on this site is offered for sale; the wanted list is the only commercial route.