Ore genesis accumulation of hematite gravels called "pisolites" which form channel-iron deposits. These are preferred because they are cheap to mine. Lead-zinc deposits are generally accompanied by silver, hosted within the lead sulfide mineral galena or within the zinc sulfide mineral sphalerite. Lead and zinc deposits are formed by discharge of deep sedimentary brine onto the sea floor (termed "sedimentary exhalative" or SEDEX), or by replacement of limestone, in skarn deposits, some associated with submarine volcanoes (called volcanogenic massive sulfide ore deposits or VMS), or in the aureole of subvolcanic intrusions of granite. The vast majority of SEDEX lead and zinc deposits
Minette (ore) low iron content, however, meant that Lotharingian Minette-ore was successively replaced by more highly concentrated imported ores (with iron contents around 60%). As a consequence, more and more mins were closed down. The last pit in Luxembourg, Differdange, closed in 1981, the last French one, at Audun-le-Tiche in the Moselle department did so in 1997. Minette (ore) Minette is a type of mineral deposit, consisting of iron ore of sedimentary origin, found in the south of Luxembourg and in Lorraine. Minette ore was deposited in the Early Jurassic and Middle Jurassic. The term "Minette" came from French miners. It is