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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 conoscopic interference pattern or interference figure is a pattern of birefringent colours crossed by dark bands (or isogyres), which can be produced using a geological petrographic microscope for the purposes of mineral identification and investigation of mineral optical and chemical properties.
The mineral is typically colorless or white, but may also be light blue, dark blue, purple, pink, red, orange, yellow or gray depending on inclusion of other materials, impurities, and structural or isotopic abnormalities in the crystals.
The most common mineral inclusion in peridot is the chromium-rich mineral chromite. Magnesium-rich minerals also can exist in the form of pyrope and magnesiochromite. These two types of mineral inclusions are typically surrounded "lily-pad" cleavages. Biotite flakes appear flat, brown, translucent, and tabular. [16]
Pyrargyrite is a sulfosalt mineral consisting of silver sulfantimonite, Ag 3 SbS 3. Known also as dark red silver ore, ruby blende, garnete blende or ruby silver, it is an important source of the metal. It is closely allied to, and isomorphous with, the corresponding sulfarsenide known as proustite or light red silver ore.
Hydrothermal ore minerals, which typically form from high temperature aqueous solutions, trap tiny bubbles of liquids or gases when cooling and forming solid rock. The trapped fluid in an inclusion preserves a record of the composition, temperature and pressure of the mineralizing environment. [1] An inclusion often contains two or more phases ...
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 ...
Minette (a type of lamprophyre), from Jáchymov in the Czech Republic. Lamprophyres (from Ancient Greek λαμπρός (lamprós) 'bright' and φύρω (phúrō) 'to mix') are uncommon, small-volume ultrapotassic igneous rocks primarily occurring as dikes, lopoliths, laccoliths, stocks, and small intrusions.