Prehnite ("casts" after Anhydrite)

Item Description

Prospect Park is one of the most famous trap rock localities on the East Coast, and certainly one of the most important specimen producers in New Jersey. I would say the most famous non-zeolite specimens from this quarry are the famous Prehnite "casts" which formed as the Prehnite covered preexisting crystals of Anhydrite, which later dissolved away, creating the hollow "casts" inside. Sometimes these "casts" will form in elongated groups, sometimes called "fingers". N.B. I'm using the term "cast" here in place of the word epimorph, but some argue this is now incorrect, and this phenomenon should properly be called a perimorph. While the argument continues, it's easier to use the word "casts" for now. Here we have a nice small cabinet sized display specimen featuring vitreous, translucent, attractive green color spherical groups of Prehnite, with one 2.2 cm long "finger" flaring up from the back. The piece is in good shape in the central portion as nearly all of the Prehnites are undamaged, and it's actually three-dimensional, which is not often the case for this material. The periphery is contacted where the piece was removed from the pocket, but this is a good quality specimen of this classic material from a now defunct locality.