Gismondine (Gismondine-Ca) (old specimen)

Item Description

This piece comes to us from an old East Coast collection, and comes with an historic label from the legendary mineral dealer, Hugh A. Ford. Since the label has Ford's New York address, it dates to 1946-1957. Gismondite is part of the Zeolite group, though the actual name Gismondite doesn't seem to be valid anymore, as now there are two species; Gismondite-(Ca) and Gismondite-(Ba). Apparently the need to differentiate between the two came out of the fact that all known Gismondite was found to be calcium-dominant until a piece of barium-dominant Gismondite was found in slag, which doesn't count because it's man made. Regardless, since the POSSIBILITY of another Gismondite existing was introduced, it was apparently decided that all of the Gismondite in the world should now be called Gismondite-(Ca) in case another anion dominant species is found. That said, here we have an attractive old time specimen of "Gismondite" from County Antrim in Northern Ireland. No specific locality was given, but there are a handful of known places where the species has been found. A cool historic specimen of this lesser known member of the Zeolite group.