These specimens come from an andesite quarry located in NE Hungary. This quarry is worked by Colas Északkő Co. In year 2013, hyaline beautiful specimens of opal were collected. In the quarry explosives are used to excavate the rocks, so most of the specimes dissapears. From summer 2015 access is not permitted, but some specimens were collected before... These facts make it difficult to see good samples of this quality.

Hyalite opal (opal-AN) aggregates (crown shaped) are completely transparent, like drops of water, with an exceptional brightness. They are highly fluorescent under shortwave UV and also under longwave. Sometimes they accompanied by globular aggregates of calcite-aragonite. They are disposed very aerial on a porous matrix of andesite.