Garnierite
Garnierite is a collective term for a green nickel ore which (mainly serpentinite ) occurs in pockets and crevices within weathered ultramafic rocks. It is formed during the lateritic weathering of ultramafic rocks and comes in numerous lateritic nickel deposits in the world before.
The name goes back to Charles Garnier, this ore in New Caledonia in 1864 discovered the first time. Since in large quantity near the capital Noumea, it was also referred to synonymously as Nouméait.
Composition
Garnierite consists of one or more minerals of the serpentine layer silicates, talc, smectite, chlorite, and sepiolite in which a significant proportion of the magnesium is replaced by nickel. For the nickel-rich varieties of these minerals are special names. A detailed investigation of garnierite ores of Falcondo mine in the Dominican Republic gave a composition of three groups of minerals: talc - Willemseite (up to 25 wt% Ni ); Lizardite ( serpentine) - Népouit (up to 34 wt% Ni ); Sepiolite - Falcondoite (up to 24 % by weight of Ni).