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Crude oil, a transformed biogenic substance Natural gum, a secretion from Hevea brasiliensis. A biogenic substance is a product made by or of life forms. While the term originally was specific to metabolite compounds that had toxic effects on other organisms, [1] it has developed to encompass any constituents, secretions, and metabolites of plants or animals. [2]
Endolith lifeform found inside an Antarctic rock. An endolith or endolithic is an organism (archaeon, bacterium, fungus, lichen, algae, sponge, or amoeba) that is able to acquire the necessary resources for growth in the inner part of a rock, [1] mineral, coral, animal shells, or in the pores between mineral grains of a rock.
Monzonite is a coarse-grained igneous rock. Such rocks are classified by their relative percentages of quartz, plagioclase, alkali feldspar, and feldspathoid (the QAPF classification). Monzonite is defined as rock having less than 5% quartz in its QAPF fraction and in which alkali feldspar makes up between 35% and 65% of the total feldspar content.
The geological definition of mineral normally excludes compounds that occur only in living beings. However, some minerals are often biogenic (such as calcite) or are organic compounds in the sense of chemistry (such as mellite). Moreover, living beings often synthesize inorganic minerals (such as hydroxylapatite) that also occur in rocks.
For example, endogenous substances, and endogenous processes are those that originate within a living system (e.g. an organism or a cell). For instance, estradiol is an endogenous estrogen hormone produced within the body, whereas ethinylestradiol is an exogenous synthetic estrogen, commonly used in birth control pills .
The original name for this phenomenon was defined by Sederholm (1923) [24] as a rock with "fragments of older rock cemented by granite", and was regarded by him to be a type of migmatite. There is a close connection between migmatites and the occurrence of ‘explosion breccias’ in schists and phyllites adjacent to diorite and granite intrusions.
Research at Argyle diamond have shown that most stones are of E-type; they originate from eclogite source rocks and were formed under high temperature ~1,400 °C (2,600 °F). The Argyle diamond mine is the main source of rare pink diamonds. Olivine lamproite pyroclastic rocks and dikes are sometimes hosts for diamonds.
Andesite is an aphanitic (fine-grained) to porphyritic (coarse-grained) igneous rock that is intermediate in its content of silica and low in alkali metals. It has less than 20% quartz and 10% feldspathoid by volume, with at least 65% of the feldspar in the rock consisting of plagioclase .