Grossular var. Caswellite with NATIVE Copper and Willemite - image 1
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Grossular var. Caswellite with NATIVE Copper and Willemite

Unknown Owner
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This interesting miniature specimen from Parker shaft at Franklin mine, New Jersey, from David Hardman's collection, could be labelled under several species as its 'main' mineral. This is because although small, at one end a sprig of Native Copper protrudes from it, and Native Copper is pretty rare at Franklin mine. Then, on the back, rich 'books' of greyish mica are the poorly defined mineral "Caswellite' believed to be a pseudomorph of Grossular after Hendricksite. Willemite is also listed as present, but the large areas of orange-brown are likely to something else entirely, perhaps Andradite. A fascinating combination specimen for Franklin enthusiasts.

Product details

SizeMiniature
Dimensions4.4 x 2.9 x 2.3 cm
Added on05/06/2026

Known provenance

DateCollectorAcquisition price
07/2026Unknown Owner$400.00
Crystal ClassicsNot disclosed

Learn more

Grossular
Mineral guide
Learn about Grossular
calcium-aluminum garnet with emerald to tsavorite greens and hessonite oranges; dodecahedra/trapezohedra in skarns, prized for color and rarity.
Regional guide
Grossular from Franklin Mine
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