Home > Copper Minerals II – September 8 > MS1117 McGuinnessite


McGuinnessite is a copper magnesium carbonate mineral, specifically a member of the rosasite group. Erd et al. (1981) named the mineral in honor of mineral dealer and amateur mineralogist Al McGuinness (1926-1990), who discovered the mineral. The mineral forms pale blue radiating growths on two surface of a metamorphosed matrix. The original host peridotite, now altered to serpentine, provided the magnesium to form the mineral. Rather rich specimen.

This specimen was part of the personal collection of Ralph Merrill, proprietor of the prolific mail order business Minerals Unlimited. Merrill obtained this specimen from Al McGuinness in 1985. Merrill's collection card and label also ship with the specimen.

Price: $40

Item code: MS1117

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