Colemanite, an Interesting Fluorescent Borate Mineral

This post features a large specimen of well-crystallized colemanite from Boron, Kern County, California.  This piece shows a bright multi-wavelength fluorescent and phosphorescent response under UV.  This size of this specimen is 15 x 11 x 8 cm and it weighs 914 grams.

 

Colemanite is a hydrated calcium borate mineral that forms in evaporite deposits of alkaline lake beds.  In addition to its fluorescence, colemanite is also a pyroelectric material, meaning that it develops an electrical charge potential in response to changes in temperature.

As shown in the photo montage above, the colemanite shows a ghostly blue/white fluorescent response under short wave UV (254 nm) followed by blue phosphorescence.  A slightly warmer white fluorescent response is seen under long wave UV (365 nm) with green phosphorescence following.

Same specimen, shown under visible light.

Please reload

Recent GlowNotes Posts

Please reload

Visit the GlowNotes Blog to view more - educational posts, equipment, minerals, photography and displays

Related Posts:

Please reload

Email comments or suggestions:

Home

RSS Feed
  • reddit
  • Facebook Social Icon

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

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!