Is wavellite fluorescent?
Is wavellite fluorescent? Its Handbook sheet prints no fluorescence, yet five society database pieces glow under 365 nm UV: white, blue or green. Test each one.
Sometimes. The Handbook of Mineralogy wavellite sheet prints no fluorescence, but the International Gem Society gives “occasionally blueish in LW”, and five Fluorescent Mineral Society database specimens all glow under 365 nm UV: white (Devon, Arkansas), blue (Arkansas, Ireland) or green (yellow Arkansas material). It belongs to the specimen, not the species.
In short
- The sheet is silent. The Handbook of Mineralogy wavellite sheet carries no fluorescence, phosphorescence or UV wording. Method: a case-insensitive search for “uoresc”, “phosphoresc”, “luminesc” and “UV”, which catches the ligature that pdftotext garbles; the same search finds the wording on the hemimorphite and willemite sheets. Silence on a sheet means nothing printed, not “inert”.
- What the sources do print. The International Gem Society wavellite article gives “Occasionally blueish in LW (various localities)”. The Fluorescent Mineral Society database has five wavellite entries; all five respond under longwave (365 nm LED): two white, two blue, one green. Under shortwave, three respond, one records none, one is not reported.
- The specimen ledger. White under all three bands with an afterglow: High Down quarry, Devon. Bluish-white under longwave, weaker under midwave, nothing under shortwave: Montgomery Co., Arkansas. Blue longwave, green shortwave: Mount Ida, Arkansas. Bright aqua blue longwave: Ballybunnion, Co. Kerry. Green under all three, brightest under shortwave: yellow wavellite from Mena, Polk Co., Arkansas.
- Documented failure: a database of glowing pieces is not a rate. Five of five is a count of specimens people chose to photograph because they glowed. The same database says Arkansas wavellite typically has a green colour and lacks fluorescence, and that not many specimens are fluorescent. Two entries from Montgomery Co., Arkansas, disagree with each other under shortwave. No source we fetched gives a proportion, and this page does not supply one.
- What to do with a piece. Record the locality, then the response under each band you own, as the database does. Background is on fluorescent minerals explained and lamps on the best UV lamp for mineral collecting. Exposure limits are in the ICNIRP 2004 guidelines on limits of exposure to ultraviolet radiation; this page is not safety advice.
| Entry | Locality (as the entry gives it) | Specimen as described | Longwave | Midwave | Shortwave | Afterglow | On the Handbook sheet? |
|---|---|---|---|---|---|---|---|
| 180 | High Down Quarry, West Buckland, North Devon, England | Radiating clusters to 2.5 cm on black chert | White | White | White | Yes; greenish after longwave | Yes: “High Down quarry, Filleigh, near South Moulton” |
| 130 | Montgomery County, Arkansas, USA | Clear and white rings in green-zoned starbursts on chert | White (bright bluish-white) | White (weaker) | None (“non-existent”) | Weak white | County only: the sheet names the Mauldin Mountain quarry near Mt. Ida, Montgomery Co. |
| 540 | Mount Ida, Montgomery County, Arkansas, USA | Not described beyond the photographs | Blue | Not reported | Green (254 nm mercury lamp) | Not reported | Yes: “near Mt. Ida, Montgomery Co.” |
| 377 | Ballybunnion, Co. Kerry, Ireland | Light blue radiating sprays in dark brown shale | Blue (bright aqua blue) | Not reported | Not reported | Not reported | No (the sheet’s Irish locality is Clonmel) |
| 129 | Mena, Polk County, Arkansas, USA | Yellow botryoidal wavellite in a vug | Green | Green | Green, most intense | Not reported | No (Polk Co. is not named) |
Does wavellite glow under UV? What the sources say
Some wavellite glows, and none of the sources we fetched says all of it does. wavellite is Al3(PO4)2(OH)3(H2O)5 on the September 2026 IMA list: orthorhombic, commonly flat to spherical radial aggregates to 3 cm, hardness 3.5 to 4, density 2.36, white streak. Its Handbook sheet prints optics, colours and localities but no luminescence wording. The search was run on the extracted text with “uoresc”, “phosphoresc”, “luminesc” and “UV”, case-insensitive; the hemimorphite sheet (“may fluoresce bluish under SW UV”) and the willemite sheet both match, so a miss on wavellite is a real miss.
The International Gem Society. Its wavellite article, by Joel E. Arem, lists under Luminescence: “Occasionally blueish in LW (various localities)”, and under Luminescence Type, “Fluorescent, UV-Long”. It does not name the localities or give a shortwave response.
The Fluorescent Mineral Society. Its database has five wavellite entries, each a single photographed specimen with the response tabulated by band. All five respond under longwave; the colours are white, blue or green. The table above gives each entry as recorded. Two of the five, from Devon and Montgomery Co., Arkansas, also record an afterglow once the lamp is off.
Why one wavellite glows and another does not
The sources attribute the glows to different traces, not to wavellite itself, and say so as attributions. The Mena entry, FMDB 129, says the yellow variant of Arkansas wavellite often fluoresces green, attributes the green to trace uranyl, and compares its shortwave spectrum with autunite’s, listing peaks at 497, 518, 541, 566 and 594 nm. The High Down entry gives a broad longwave peak centred at 463 nm and calls an organic activator the probable source; the Montgomery Co. entry gives a broad peak near 450 nm and names dissolved organic compounds as potential activators. These are each contributor’s interpretation, reported here as theirs.
Documented failure: same county, different answers. Two entries from Montgomery Co., Arkansas, disagree under shortwave: one records no response, the other green under a 254 nm mercury lamp. Within one specimen, the Montgomery Co. starbursts glow in their clear and white rings and the High Down clusters most brightly at their outer rims. Neither species nor locality settles whether a given piece will respond.
Uranyl and radioactivity. The IMA formula contains no uranium; the Mena entry’s attribution is to a trace. Whether a particular piece is measurably radioactive is a separate question, covered on is my mineral radioactive; this page gives no radiation figures and is not advice. The general mechanism of activators and quenchers is on fluorescent minerals explained.
How to check a wavellite under UV: the specimen ledger method
Treat fluorescence as a recorded observation about one specimen, the way the database does: locality, band, colour, afterglow. Under each band you have, note the response or its absence; with a longwave lamp only, a blank under shortwave is “not tested”, not “none”. The Montgomery Co. pair shows why the shortwave column matters. Lamp bands and filters are compared on the best UV lamp for mineral collecting; is hemimorphite UV reactive covers a species whose sheet does print a response.
What a glow does and does not identify. A white, blue or green glow is consistent with wavellite but proves nothing: the sheet gives no response to match, and its look-alikes variscite and turquoise print none either on their sheets. Identification rests on the sheet’s numbers: hardness 3.5 to 4 and a 20.00 g piece reading 11.53 g in water, as on the wavellite page. A dark piece that does nothing under any lamp is still wavellite if those fit.
Safety, in one line. Exposure limits for 180 to 400 nm are set out in the ICNIRP 2004 guidelines on limits of exposure to ultraviolet radiation; this page is not safety advice, and hazards in general are routed to toxic minerals in a collection. More guides are in the collecting guides. Nothing on this site is offered for sale; the wanted list is the only commercial route.