Synthetic Fluorescent Mineral Experiment: Uranyl Based Fluorescence - UVa

FOV: 6" wide.

 

This experiment demonstrates the shift in color from yellow-green to blue-green of minerals containing the uranyl ion in conjunction with carbonates.

 

Uranyl nitrate was combined with NaCl and recrystallized on the glass rod. Behind it is a specimen of meta-autunite from the Daybreak Mine in Spokane WA, USA. Meta-autunite is a uranyl phosphate mineral.

 

Uranyl nitrate solution (0.25M) was combined with a sodium carbonate solution (1.25M) and was used to rehydrate some DAP Plaster of Paris mix which was set in a square mold.

 

Initially (when still wet), there was no fluorescence but after the calcium sulfate re-hydrated (and the mix produced CO2? bubbles), the resulting plaster fluoresced a bright blue-green, typical of carbonate based uranyl minerals. Behind the plaster square is a specimen with a coating of andersonite from Yellow Cat Mesa in Grant County UT, USA. Andersonite is a hydrated sodium calcium uranyl carbonate.

 

See:

en.wikipedia.org/wiki/Andersonite

rruff.info/uploads/CM31_167.pdf

 

Contains:

Andersonite (FL Blue-green >BL/UVabc)

Meta Autunite (FL Yellow-green >BL/UVabc)

 

Shown under UVa light.

 

Key:

WL = White light (halogen + LED)

FL = Fluoresces

PHOS = Phosphorescent

Blue = 450nm,

UVa = 368nm (LW), UVb = 311nm (MW), UVc = 254nm (SW)

'>' = "stimulated by:", '!' = "bright", '~' = "dim"

 

Uranyl Based Fluorescence

6Nov2015

 

Much appreciation to Gordon Czop for the uranyl nitrate.

 

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Photostream best viewed in Lightbox mode (in the dark).

 

18 Watt Triple Output UV lamp from Polman Minerals - Way Too Cool UV lamps

Done