Cumulate Texture
Cumulate rocks are igneous rocks formed by the accumulation of crystals from a magma either by settling or floating. Cumulate rocks are named according to their rock microstructure, texture; cumulate texture is diagnostic of the conditions of formation of this group of igneous rocks. Cumulates can be deposited on top of other older cumulates of different composition and colour, typically giving the cumulate rock a layered or banded appearance. Formation Cumulate rocks are the typical product of precipitation of solid crystals from a Fractional crystallization (geology), fractionating magma Magma () is the molten or semi-molten natural material from which all igneous rocks are formed. Magma is found beneath the surface of the Earth, and evidence of magmatism has also been discovered on other terrestrial planets and some natural sa ... chamber. These accumulations typically occur on the floor of the magma chamber, although they are possible on the roofs if anorthite plagioclase ...
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Sulfidic Norite (platinum-palladium Ore) Stillwater Mine MT
Sulfidation (British spelling also sulphidation) is a process of installing sulfide ions in a material or molecule. The process is widely used to convert oxides to sulfides but is also related to corrosion and surface modification. Inorganic, materials, and organic chemistry Sulfidation is relevant to the formation of sulfide minerals. A large scale application of sulfidation is the conversion of molybdenum oxides to the corresponding sulfides. This conversion is a step in the preparation of catalysts for hydrodesulfurization wherein alumina impregnated with molybdate salts are converted to molybdenum disulfide by the action of hydrogen sulfide. In organosulfur chemistry, sulfiding is often called thiation. The preparation of thioamides from amides involves thiation. A typical reagent is phosphorus pentasulfide (P4S10). The idealized equation for this conversion is: :RC(O)NH2 + 1/4 P4S10 → RC(S)NH2 + 1/4 P4S6O4 This conversion where an oxygen atom in the amide fun ...
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