Daylight Fluorescent Hyalite Opal, Zacatecas, Mexico

Colorless to greenish, transparent, glassy bubbles of hyalite opal (Opal-AN) covering an unknown brown/grey colored matrix, from Electric Opal Knob, Zacatecas, Mexico. The hyalite opal shows a bright green fluorescent response under both SW and LW UV, and also exhibits yellow/green daylight fluorescence. The green fluorescent response seen in this material is due to trace amounts of uranium included in the opal silica. Due to the uranium content, this specimen is moderately radioactive and was measured at 200-300 cpm at 1 cm. The size of this piece is 10.1 x 6.71 x 3.81 cm, and it weighs 165 grams.

The Electric Opal Claim in Zacatecas, Mexico produced specimens of hyalite opal that were notable for having brilliant green fluorescence under UV, and bright green daylight fluorescence when viewed under shaded daylight outside. The Electric Opal Claim produced many high quality specimens of this material between 2013 and 2018, but due to the limited size of the opal-bearing layer, has been subsequently mined out.

Mouse over scrolling images for captions.

24 views0 comments

Email comments or suggestions:


Nature’s Rainbows is a non-commercial web site maintained entirely by volunteer hobbyists and contributors.  Our mission is to provide information about UV and luminescence, premium fluorescent mineral photos, and a fluorescent mineral database for the enjoyment of FL mineral collectors around the world.  Information on this web site is covered under a Creative Commons License.

Feel free to contact us with comments and suggestions.

Like us on Facebook!

  • reddit
  • Facebook Social Icon

Subscribe to our RSS (Real Simple Syndication) feed to get new posts delivered directly to your desktop!