Database of luminescent Minerals


Chemical Formula:See chalcedony

Familly: Oxides and hydroxides

Status: NON APPR

Crystal System: Polycrystalline

Mineral for Display: Yes


UV Type Main color Intensity Observation Frequency
Short Waves (254 nm):      Green Medium

Daylight Picture

youngite,Photo and Copyright: Paul Garland
Pictures on Flickr:
Used with permission of the author

Short Waves Pictures (254nm)

youngite under UVSW,Photo and Copyright: Paul Garland
Pictures on Flickr:
Used with permission of the author


Galerie de photos:


     To the gallery (2 images in the gallery)

Phosphorescence (in the common meaning of the term) seen by naked eye:

No Data


Youngite is a local name applied to brecciated chalcedony-jasper rocks covered by druzy quartz crystals. It is found in natural caves and veins in Mississippian limestone near Glendo and Guernsey reservoirs in Platte County, Wyoming, USA.

Youngite consists of red, yellow, chocolate, lilac, peach, gold, cream, orange, and purple jasper fragments within a matrix of off-white to grayish-blue chalcedony.

Main Activator(s) and spectrum:

Most Common Activator: (UO2)2+ (Uranyl ion) as impurities

Peaks in the spectrum (nm):

UO22+ : 499nm, 522nm, 544nm

567, 594, 601nm (?) 

Col. G. Barmarin; Spectre: G. Barmarin

Best Locality for luminescence(*):

(*)Data are not exhaustive and are limited to the most important localities for fluorescence

Bibliographical Reference for luminescence:

Mineralogical Reference on internet:

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Note: While all due attention has been paid to the implementation of the database, it may contain errors and/or accidental omissions. By nature, the database will always be incomplete because science always evolves according to new analysis.
A request providing no result means only that no such reference exists in the database, but it does not mean that what you are looking for does not exist, just not to our knowledge. If you think you have found an error or omission, please let us know via the contact page being sure to cite the source of information.


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