Opal-AN - image 1
Opal-AN - image 2

Opal-AN

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Glassy colorless bubbly opal across matrix. Brightly fluorescent as shown in the photo. The video shows the sample in normal daylight. In great condition. The Kopasz Hill quarry near Tarcal, situated in the Tokaj Mountains of Borsod-Abauj-Zemplen County, Hungary, is an active or intermittently operated commercial andesite aggregate quarry where intensive mineral collecting phases peaked around 2013 to 2015 before access was officially closed to collectors. Geologically, the site is defined by Miocene calc-alkaline volcanic formations, where andesite and related volcanic rocks contain hydrothermal alteration zones, veins, and cavities that host secondary silica deposition. The quarry became globally famous among mineral enthusiasts for exceptional water-clear hyalite, a form of opal-AN, which coats fracture zones and mineral surfaces. Under shortwave (SW) ultraviolet light, this hyalite opal exhibits a brilliant and intense neon green fluorescence, frequently accompanied by associated minor calcite or aragonite that display contrasting yellow or bluish responses under longer UV wavelengths.

Product details

SpeciesOpal
SizeSmall Cabinet
Dimensions6.5 x 5.0 x 3.5 cm
Added on09/15/2026
Current owner
Unknown Owner
Acquired
Sep 2026
Previous owners
DateCollectorAcquisition price
—Weinrich MineralsNot disclosed

Learn more

Opal
Mineral guide
Learn about Opal
amorphous silica with water and a spectacular play-of-color; black, boulder, and fire opal varieties capture brightness, color, and collecting appeal.
Opal
Regional guide
Opal from Kopasz Hill andesite quarry
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Locality guide
Kopasz Hill andesite quarry
A collector's guide to Kopasz Hill andesite quarry, Hungary: its geology, mining history and notable minerals, illustrated with the 93 specimens documented from this locality on EarthWonders.