In 1991 a sphalerite mining operation near Balmat, New York, encountered an altered area containing cubic to tetrahexahedral magnetite crystals in halite-filled veins.
Because magnetite crystals of cubic and tetrahexahedral habit are so rare worldwide, we investigated their crystal habits at this locality in more detail (Chamberlain and Robinson 1993; Morgan, et al.
We are aware of no other localities for magnetite crystals with a predominantly tetrahexahedral habit.
However, dodecahedral, hexoctahedral, tetrahexahedral
and other modifications of the cube have been found, and at Delphos and Lima unusual botryoidal-appearing clusters of cubic crystals and needles have been found in the same geologic layer.
The fluorite comes in lovely groups of simple cubic crystals - though some cubes are flattened, and some are not so simple, being attractively modified by tetrahexahedral
"riser" faces, four around each cube face.
It has also been found by this writer in microscopic apple-green crystals associated with glassy cerussite crystals, corroded galena, quartz and tetrahexahedral
purple fluorite from a single sandstone boulder on the dump of the Rosiclare Lead and Spar Company mill.
Other interesting finds made by John over the past year include some complex fluorite crystals from the Auglaise quarry, showing tetrahexahedral
and hexoctahedral faces, some good strontianite specimens from Lime City, and some complex pyrite crystals from Duff's quarry, near Huntsville.