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Pyrite cubic crystals on marl from Navajún, La Rioja, Spain (size: 95 by 78 millimetres [3.7 by 3.1 in], 512 grams [18.1 oz]; main crystal: 31 millimetres [1.2 in] on edge) Pyrite's metallic luster and pale brass-yellow hue give it a superficial resemblance to gold, hence the well-known nickname of fool's gold.
The group is named for its most common member, pyrite (fool's gold), which is sometimes explicitly distinguished from the group's other members as iron pyrite. Pyrrhotite (magnetic pyrite) is magnetic, and is composed of iron and sulfur , but it has a different structure and is not in the pyrite group.
Ruthenium can be oxidized to ruthenium(IV) oxide (RuO 2, oxidation state +4), which can, in turn, be oxidized by sodium metaperiodate to the volatile yellow tetrahedral ruthenium tetroxide, RuO 4, an aggressive, strong oxidizing agent with structure and properties analogous to osmium tetroxide.
The mineralogy of VMS consists of over 90% iron sulfide, mainly in the form of pyrite, with chalcopyrite, sphalerite and galena also being major constituents. Magnetite is present in minor amounts; as magnetite content increases, the ores grade into massive oxide deposits. The gangue (the uneconomic waste material) is mainly quartz and pyrite ...
The oxide mineral class includes those minerals in which the oxide anion (O 2−) is bonded to one or more metal alloys. The hydroxide -bearing minerals are typically included in the oxide class. Minerals with complex anion groups such as the silicates , sulfates , carbonates and phosphates are classed separately.
Pressure oxidation is a process for extracting gold from refractory ore.. The most common refractory ores are pyrite and arsenopyrite, which are sulfide ores that trap the gold within them.
These include ε-FeOOH, which has an orthorhombic crystal structure, [10] a cubic pyrite-type polymorph with [11] or without losing hydrogen [12] and an ultradense hexagonal structure. [13] Goethite has the same crystal structure as diaspore, the analogous aluminium oxide-hydroxide mineral. Oxygen and hydroxide ions form a hexagonal close ...
Metal sulfides (e.g., pyrite FeS 2, arsenopyrite FeAsS, chalcopyrite CuFeS 2) are normally processed by chemical oxidation either in aqueous media or at high temperatures. In fact, most base metals, e.g., aluminium, chromium, must be (electro)chemically reduced at high temperatures by which the process entails a high energy demand, and ...