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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.
Also, the mineral pyrite is both the most common and most abundant sulfide mineral in the Earth's crust. [6] If rocks containing pyrite undergo metamorphism, there is a gradual release of volatile components like water and sulfur from pyrite. [6] The loss of sulfur causes pyrite to recrystallize into pyrrhotite. [6]
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.
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 ...
In this case, the pyrite has dissolved away yielding a cube shape and residual gold. This break down is the main driver of acid mine drainage. Sub-surface mining often progresses below the water table, so water must be constantly pumped out of the mine in order to prevent flooding. When a mine is abandoned, the pumping ceases, and water floods ...
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 ...