Apple Green Willemite, Franklin, New Jersey

This is a variety of willemite from Franklin, New Jersey called "apple green willemite" for its, well... apple green color. This is one of the brightest fluorescing minerals when viewed under short wave UV, producing a brilliant green response. It also shows a phenomenon known as daylight fluorescence, meaning that when viewed in the daylight outside, the UV component of sunlight activates the green fluorescent response which is visible as a brightening of the green color of the specimen. This piece also shows respectable green fluorescence under long wave UV. This specimen is about fist-sized, and measures 100 x 86 x 59 mm and weighs 866 grams.

Apple green willemite from the Franklin Mine, shown under visible light.

In the above photgraph, the specimen shows brilliant green fluorescence under short wave UV (254 nm).

The fluorescence of willemite under long wave UV (365 nm) is highly variable, but as seen in the photograph above, this piece shows a bright green response.

45 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!