Opal var: Opal-AN (formerly ''Hyalite Opal'') (fluorescent)

Item Description

Here we have a beautiful gemmy Opal specimen from the Erongo Mountains of Namibia. For many years, these gemmy botryoidal Opals were labeled as "Hyalite", but recently the material has been re-classified as Opal-AN, a variety of Opal which forms as a series of dissimilarly-sized nanospheres of silica that measure less than 5 nm in diameter, according to entry on mindat.org. This specimen is filled with dozens of spherical aggregates of very gemmy, colorless to light yellow-green colored Opal-AN, covering a good portion of the matrix on this small cabinet sized specimen. Additionally, one of the characteristics of this material is that it is often is highly fluorescent, and this piece shows a glowing electric green color under SW UV light. A really cool and desirable specimen of this beautiful material that is pegmatitic in origin, not volcanic, like most Opal-AN specimens.