Occurrence
Gageite, named after R. B. Gage, of Trenton, N.J., and first described in a preliminary paper by Phillips (197), was found, associated with zincite, willemite, calcite, and leucophoenicite, in specimens from the Parker shaft. The crystals are described as showing faces under the microscope, but none were measured and no optical data were given.

The best-defined specimens of gageite known to the author are those described at length under pyrochroite (see page 50), which contain distinct crystals with square cross sections but no measurable faces. Their optical characters, determined by Larsen, established their identity with type material studied by him. It has also been determined by optical methods as constituting coatings of silky fibrous appearance and bronze color in cracks in massive ore from the Franklin mines, but sufficient material for a confirmatory analysis has not been found.

In recent years gageite has been found abundantly at Franklin, especially associated with the arsenate chlorophoenicite. It forms pale-pinkish, fibrous aggregates and seems to be a replacement product or a pseudomorph after some unidentified mineral. One specimen, supplied by Captain Rowe, contained sufficient material in a pure state to furnish a gram sample, of which an analysis was made. As Gage's original analysis was made on a very small sample, the confirmation of the composition of the mineral by the new analysis was gratifying.