Refractory Inclusion

Inclusions found predominantly in carbonaceous chondritesChondrites are the most common meteorites accounting for ~84% of falls. Chondrites are comprised mostly of Fe- and Mg-bearing silicate minerals (found in both chondrules and fine grained matrix), reduced Fe/Ni metal (found in various states like large blebs, small grains and/or even chondrule rims), and various refractory inclusions (such and are rich in refractory elementsUsing research by Wood (2019), any of the elements with a relatively high condensation temperature of 1291 K < TC,50 < 1806 K in the solar nebula1. They are the first elements to condense out of a cooling gas. Refractory elements are the main building blocks of rocky planets, dwarf particularly calcium, aluminum and titanium that in various combinations form minerals such as spinelMg-Al oxide, MgAl2O4, found in CAIs., meliliteGroup of minerals found in the CAIs of meteorites such as CV chondrites. Melilite consists almost exclusively of the binary solid solution gehlenite (Ca2Al2SiO7) – åkermanite (Ca2MgSi2O7). The melilite in CAIs is closer to gehlenite in composition. The first-formed (highest-temperature) melilite crystallizing from a melt is relatively aluminum-rich and becomes progressively, perovskiteTerm applied to A2+B4+O3 high-pressure minerals with a perovskite structure (general formula ABX3) where "A" is a metal that forms large cations such as Mg, Fe or Ca, "B" is another metal that forms smaller cations such as Si (called silicate perovskite), Ti and to a lesser degree Al, and and hiboniteRefractory mineral, Ca-aluminate (CaAl12O19) that occurs in terrestrial metamorphic rocks and in CAIs of many chondrites. Meteoritic hibonite tends to be blue as seen in the meteorite Isheyevo (Ch/CB). Hibonite is one of the most refractory minerals found in primitive meteorites.. There are two types of refractory inclusionFragment of foreign (xeno-) material enclosed within the primary matrix of a rock or meteorite.:

1. Ca Al-rich inclusionsSub-millimeter to centimeter-sized amorphous objects found typically in carbonaceous chondrites and ranging in color from white to greyish white and even light pink. CAIs have occasionally been found in ordinary chondrites, such as the L3.00 chondrite, NWA 8276 (Sara Russell, 2016). CAIs are also known as refractory inclusions since they (CAIsSub-millimeter to centimeter-sized amorphous objects found typically in carbonaceous chondrites and ranging in color from white to greyish white and even light pink. CAIs have occasionally been found in ordinary chondrites, such as the L3.00 chondrite, NWA 8276 (Sara Russell, 2016). CAIs are also known as refractory inclusions since they)
2. Amoeboid olivine aggregatesMillimeter sized, fine-grained inclusions present to a few volume-percent in most carbonaceous chondrites. They can be round but can also be irregularly shaped like an amoeba (thus the name amoeboid). They are forsterite (Mg-rich olivine) and Ca-Al-Ti mineral aggregates. The most characteristic texture of AOAs is an anorthite core (sometimes (AOAs)

Refractory inclusions were the first solids to condense from within the hot inner protoplanetary diskFlattened and rotating disk of dense gas and dust/solids orbiting a young star from which planets can eventually form.  . As such, they provide evidence of the earliest thermal and chemical processing, as well as preserve the isotopic signatures of the presolar material within the dust and gas clouds that would later form the SunOur parent star. The structure of Sun's interior is the result of the hydrostatic equilibrium between gravity and the pressure of the gas. The interior consists of three shells: the core, radiative region, and convective region. Image source: http://eclipse99.nasa.gov/pages/SunActiv.html. The core is the hot, dense central region in which the and our planetary systemDefinable part of the universe that can be open, closed, or isolated. An open system exchanges both matter and energy with its surroundings. A closed system can only exchange energy with its surroundings; it has walls through which heat can pass. An isolated system cannot exchange energy or matter with. Their shape and textures vary from irregular structures suggestive of gaseous condensates, to more compact and rounded structures that may have derived from melts or partial melts that slowly cooled over a period of days.¹