An fascinating Hyalite Opal gemstone from Zacatecus, Mexico with the characteristic strong Fluorescence associated with gems from this prime locale.
The gem appears a very pale green colour in indoor lighting, a slightly stronger green in direct daylight.
It reverts to an electric green colour when exposed to either long-wave or short-wave ultraviolet light. (Images 1 and 5 taken in L/W UV, image 6 in S/W).
To see a short video of the fluorescent transformation of the gem on YouTube please use this link:
The gem has a very faint inclusion scene (not visible by eye) which consists of contoured flow lines. Magnified images 7 and 8 show the interior scene in white and L/W UV light.
Zacatecus is the source of the finest of this uncommon Opal variety and this is an excellent example of an extremely rare and collectible gemstone.
weight: 0.93 carat
shape: Cushion shape cut
dimensions: 7.21 x 6.40 x 4.25 mm