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A mafic mineral or rock is a silicate mineral or igneous rock rich in magnesium and iron. Most mafic minerals are dark in color, and common rock-forming mafic minerals include olivine, pyroxene, amphibole, and biotite. Common mafic rocks include basalt, diabase and gabbro. Mafic rocks often also contain calcium-rich varieties of plagioclase ...
Clay minerals are hydrous aluminium phyllosilicates (e.g. kaolin, Al 2 Si 2 O 5 4), sometimes with variable amounts of iron, magnesium, alkali metals, alkaline earths, and other cations found on or near some planetary surfaces. Clay minerals form in the presence of water [1] and have been important to life, and many theories of abiogenesis ...
Serpentine subgroup is a set of common rock-forming hydrous magnesium iron phyllosilicate ((Mg,Fe) 3 Si 2 O 5 4) minerals, resulting from the metamorphism of the minerals that are contained in mafic to ultramafic rocks. [6] They may contain minor amounts of other elements including chromium, manganese, cobalt or nickel.
On the other hand, some substances that have a continuous series of compositions, may be arbitrarily split into several minerals. The typical example is the olivine group (Mg, Fe) 2 SiO 4, whose magnesium-rich and iron-rich end-members are considered separate minerals (forsterite and fayalite). The details of these rules are somewhat ...
Cretaceous iron-rich laterite (the dark unit) in Hamakhtesh Hagadol, southern Israel. Ores are concentrated in metalliferous laterites; aluminum is found in bauxites, iron and manganese are found in iron-rich hard crusts, nickel and copper are found in disintegrated rocks, and gold is found in mottled clays. [6]: 2
The above classification scheme is the most commonly used and accepted, though sometimes an older system is used which divides iron-rich sedimentary rocks into three categories: bog iron deposits, ironstones, and iron formations. A bog-iron deposit is iron that formed in a bog or swamp through the process of oxidation.
Diets rich in four different types of nutrients may help reduce iron buildup in the brain and lower the risk of cognitive decline that comes with aging, a new study suggests.
Acidic water rich in iron then dissolve the calcite leaving behind the iron rich (hematite) spherule. This leads to the conclusion that the blueberries may have formed early in Mars's history when the atmosphere was more dense by the same process.