Gaspeite

Gaspeite is a rare nickel carbonate that forms as a secondary mineral in the oxidation zone of nickel sulfide ore deposits. When primary nickel minerals like pentlandite and millerite are exposed to weathering, the released nickel combines with carbonate-rich groundwater to precipitate gaspeite.

The vivid apple-green to lime-green color comes directly from the nickel content. This makes gaspeite one of the few bright green minerals whose color isn't caused by copper or chromium. The green is distinctive: a warm, yellowish apple-green quite different from the blue-greens of copper minerals.

First described in 1966 from the Gaspé Peninsula in Quebec, Canada, gaspeite gained popularity in the jewelry market through Australian Aboriginal artists who used it alongside turquoise and coral in silver jewelry. The Western Australian nickel mining regions produce the majority of lapidary-grade material.

Gaspeite is identified by its bright apple-green color, relatively high specific gravity for a carbonate (3.71, noticeably heavy), and effervescence in warm dilute hydrochloric acid. The distinctive yellow-green rather than blue-green separates it from most copper minerals.

Distinguish from chrysoprase (much harder, quartz family), turquoise (blue-green, phosphate not carbonate), and dyed magnesite (lighter SG, different acid reaction). Gaspeite's combination of green color, high SG, and carbonate acid reaction is diagnostic.