news out serra verde, page-30

JW, as Zachary said the sulphides in the picture are chalcopyrite (+ some pyrite by the looks of it). That 1st picture is dark mafic (basaltic) rock with stringers of massive chalcopyrite. Chalcocite, when formed as a result of oxidation of primary Cu sulphides, forms a matte black mineral that is commonly associated with malachite (bright green). When chalcocite forms as a primary Cu sulphide as part of the original mineralisation process it is a shiny silver colour.

Massive, when referring to sulphides is a qualifier of abundance within an interval. Massive generally refers to sulphides that are greater than 80% of the intersection. It doesn't necessarily mean that there is metres and metres of the stuff. You can have massive sulphides only a few cm thick.

Also some Cu contents for 100% sulphides; chalcopyrite = 33%Cu, Bornite = 50%Cu, chalcocite = 66%Cu.

Onward and Upwards :D