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In mineralogy, an inclusion is any material trapped inside a mineral during its formation. In gemology , it is an object enclosed within a gemstone or reaching its surface from the interior. [ 1 ] According to James Hutton 's law of inclusions, fragments included in a host rock are older than the host rock itself.
A study of sodium-rich quartz-alkali feldspar—biotite gneiss granulite facies terrane in the Kerala Khondalite Belt near Manali in south India found that in situ leucosomes (light colored segregations) within the gneiss showed the development of garnet replacing the dark biotite. The study indicated localized melting or migmatization within ...
Agrominerals (also known as stone bread or petrol fertilizer) are minerals of importance to agriculture and horticulture industries for they can provide essential plant nutrients. [1] Some agrominerals occur naturally or can be processed to be used as alternative fertilizers or soil amendments . [ 1 ]
Terra preta (Portuguese pronunciation: [ˈtɛʁɐ ˈpɾetɐ], literally "black soil" in Portuguese), also known as Amazonian dark earth or Indian black earth, is a type of very dark, fertile anthropogenic soil found in the Amazon Basin.
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 ...
Dark soil color imparted by organic matter in Illinois, US. Dark brown or black colors typically indicate that the soil has a high organic matter content. [4] Organic matter coats mineral soil particles, which masks or darkens the natural mineral colors. [1] Sodium content also influences the depth of organic matter and therefore the soil color.
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It is a dark grey metallic mineral which forms acicular prismatic monoclinic crystals. It is soft with a Mohs hardness of 2.5 and has a specific gravity of 5.5 – 5.6. [5] It is one of the few sulphide minerals to form fibrous or needle like crystals. It can also form large prismatic crystals similar to stibnite with which it can be associated.