Molds and Pseudomorphs

The NJ basalts went through quite a bit of change during the various periods of mineralization.

The deposits are famous for their molds of the original minerals from the first phase of deposition- Anhydrite and Glauberite.  Most often the minerals overgrowing these species were Quartz and Prehnite. Later dissolution of the poriginal crystals by warm solutions results in structures shown here. It is not uncomon in some zones to find crystal shaped molds in the basalt itself, some refilled and some not.

Pseudomorphs are less common but still widespread. The preliminary list below indicates some recovered in recent years.
Anhydrite Mold in Smoky Quartz
Upper New St.
Stilbite filling Glauberite mold in Quartz
Upper New St.
------- Molds of Anhydrite in Amethyst
Calcite pseudomorph of rhombic mineral- possibly earlier Calcite      ----------
Preliminary Pseudomorph List

Chalcedony after Anhydrite- Upper New St.
Calcite after Anhydrite- Upper New St
Calcite after rhombic ?- Millington
Chrysocolla after Chalcocite (?)- Houdaille Great Notch