Is adamite UV reactive
Adamite may fluoresce and phosphoresce lemon-yellow under SW and LW UV, its Handbook sheet says. In a 1948 test 2 of 7 lots glowed, Ojuela far weaker under LW.
Is adamite UV reactive? Sometimes. Its Handbook sheet says it may fluoresce and phosphoresce lemon-yellow under shortwave and longwave UV; hardness 3.5. In a 1948 study, adamite from the Ojuela mine, Mapimí, glowed bright lemon-yellow under shortwave and much more weakly under longwave, and five of the seven lots tested gave nothing.
In short
- The sheet says may, and it names both bands. The Handbook reads May fluoresce and phosphoresce lemon-yellow under SW and LW UV. Phosphorescence is the afterglow once the lamp goes off.
- The count: 31 of the 176 sheets in this site's reference set record fluorescence, and 11 name both bands. Only 4 record both bands and phosphorescence: adamite, aragonite, calcite and willemite. Three name lemon-yellow emission: adamite, polylithionite and saleeite.
- The 1948 tests show how uneven it is. Mrose, Mayers and Wise tested seven lots. Ojuela adamite fluoresced bright lemon yellow with a pale lemon-yellow phosphorescence under shortwave, and much more weakly under longwave. A blue-green Laurium specimen gave a weak greenish glow under both. The other five gave nothing.
- Colour did not sort the results cleanly. The negatives were a colourless Laurium specimen, a blue-green Gold Hill specimen, cobaltian material from Cap Garonne and Tsumeb, and cuprian material from Tsumeb. One cuprian lot is one lot, so the tests suggest rather than prove that green adamite is less likely to glow.
- Shortwave first. The sheet treats the bands alike; the only measured comparison verified for this page found longwave much weaker on Ojuela material. Adamite's own associates on the sheet include three fluorescent species, so check what on the specimen is glowing.
| Species | Formula as the sheet prints it | Fluorescence as recorded | Bands named | Phosphorescence recorded | Hardness |
|---|---|---|---|---|---|
| Adamite | Zn2(AsO4)(OH) | May fluoresce and phosphoresce lemon-yellow | SW and LW | May | 3.5 |
| Willemite | Zn2SiO4 | Typically strongly fluorescent, yellow-green to yellow-orange | SW and LW | May be | 5.5 |
| Calcite | CaCO3 | May fluoresce red, blue, yellow and other colors | SW and LW | Yes | 3 |
| Aragonite | CaCO3 | Fluorescent red or yellow | LW and SW | Yes | 3.5 to 4 |
| Mimetite | Pb5(AsO4)3Cl | May fluoresce reddish yellow | LW or SW | None recorded | 3.5 to 4 |
| Pyromorphite | Pb5(PO4)3Cl | May fluoresce yellow to orange | LW and SW | None recorded | 3.5 to 4 |
| Saleeite | Mg(UO2)2(PO4)2·10H2O | Fluoresces bright lemon-yellow (LW), pale yellow (SW) | LW and SW | None recorded | 2 to 3 |
| Scolecite | CaAl2Si3O10·3H2O | May fluoresce yellow to brown | SW and LW | None recorded | 5 to 5.5 |
| Grossular | Ca3Al2(SiO4)3 | May fluoresce weak golden yellow | LW or SW | None recorded | 6.5 to 7 |
| Marialite | 3NaAlSi3O8·NaCl | Commonly orange to bright yellow or red | LW or SW or both | None recorded | 5.5 to 6 |
| Meionite | 3CaAl2Si2O8·CaCO3 | Commonly orange to bright yellow or red | LW or SW or both | None recorded | 5 to 6 |
Is adamite UV reactive? The sheet line, and the 31-sheet count
Definition first: a UV-reactive mineral fluoresces, giving off visible light while an ultraviolet lamp is on it, and adamite's Handbook of Mineralogy sheet says it may, in lemon-yellow, under both shortwave (SW) and longwave (LW), and may also phosphoresce. The word may is the boundary: it is a property of some specimens, not of the species.
Method. The 176 sheets in this site's reference set were converted with pdftotext -layout and searched for fluoresc ligature-aware, because older sheets render the fl as a stray glyph. Hemimorphite and willemite, both typeset that way, had to match as positive controls, and did. 31 sheets record fluorescence; a literal search finds only 21. Eleven name both bands, six shortwave only, two longwave only and twelve no band. Four of the 176 record both bands and phosphorescence: adamite, aragonite, calcite and willemite.
Among arsenates, adamite is in a small group. Eleven sheets have AsO4 in the formula and two record fluorescence: adamite and mimetite. Olivenite, the copper end of adamite's series, records none, and neither does scorodite; of the lead species collectors also ask about, wulfenite and vanadinite record none. Pyromorphite does, under both bands.
Does all adamite fluoresce? Seven lots tested in 1948
No. In the 1948 study cited on the Handbook sheet, 2 of 7 lots of adamite responded under ultraviolet. Mrose, Mayers and Wise, in American Mineralogist 33, reported:
- Ojuela mine, Mapimí, Mexico: bright lemon yellow fluorescence with a pale lemon-yellow phosphorescence under shortwave; a much weaker reaction under longwave. Small crystals on those specimens were nearly colourless and larger ones greenish-yellow.
- Laurium, Greece, a blue-green specimen: weak greenish fluorescence under both longwave and shortwave.
- No response: a colourless specimen from Laurium, a blue-green specimen from Gold Hill, Utah, cobaltian material from Cap Garonne, France and from Tsumeb, and cuprian material from Tsumeb.
That is one laboratory's sample from 1948, not a survey of adamite. It shows that a non-fluorescent adamite is normal, and that Ojuela, the locality the sheet names for large crystals, gave the strongest response. The site's adamite page attributes the green material's weaker response to copper. In these tests the one cuprian lot gave nothing, but so did a colourless one, and a blue-green one glowed, so colour alone did not predict the result. Tsumeb material was negative in both tested forms.
Shortwave or longwave for adamite? What each source says
The sheet names both bands without ranking them; the 1948 paper found Ojuela adamite much weaker under longwave. Those are not in conflict: may fluoresce under SW and LW says either can work, and the measurement says which worked better on one locality. On that evidence, test under shortwave first and do not read a dark longwave result as a negative.
Test the lamp before the specimen. A known shortwave fluorescer such as Franklin willemite settles whether the equipment works; the method, and why a filtered lamp matters, is on is fluorite UV reactive and fluorescent minerals explained, and is not repeated here. Lamp choice is on the best UV lamp for mineral collecting.
Shortwave is the band with the eye hazard. Exposure limits across 180 to 400 nm, covering both collecting bands, are in the ICNIRP 2004 guidelines. This page points at them and gives no safety advice of its own.
When adamite glows, check what else on the specimen is glowing
Adamite's sheet lists its associates as smithsonite, hemimorphite, scorodite, olivenite, calcite, quartz and Fe-Mn oxides; three of those six species record fluorescence. Smithsonite may fluoresce pale green or pale blue with no band named, hemimorphite may fluoresce bluish under shortwave, and calcite may fluoresce in several colours under both bands. Scorodite, olivenite and quartz record none. A glow on an oxidised-zone zinc specimen can come from the matrix as easily as from the adamite; the zinc-carbonate version of this problem is on is smithsonite UV reactive.
Fluorescence is not radioactivity. Adamite's formula contains no uranium; the distinction is on is my mineral radioactive. It is an arsenate, 26.13% arsenic by mass calculated from Zn2(AsO4)(OH), and arsenates are covered on toxic minerals in a collection; this page gives no handling advice. British localities on the sheet are Cornwall and Caldbeck Fells.
The fluorescence pages are indexed at the collecting guides. Nothing on this site is offered for sale; the wanted list is the only commercial route.