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When a rock undergoes partial melting some minerals will melt (neosome, i.e. newly formed), while others remain solid (paleosome, i.e. older formation). The neosome is composed of lightly colored areas (leucosome) and dark areas (melanosome). The leucosome lies in the center of the layers and is mainly composed of quartz and feldspar.
This is a list of minerals which have Wikipedia articles. Minerals are distinguished by various chemical and physical properties. Differences in chemical composition and crystal structure distinguish the various species .
This is a list of gemstones, organized by species and types. Minerals ... Some minerals made into gemstones may display a chatoyancy or cat's eye effect, ...
Optical properties of common minerals Name Crystal system Indicatrix Optical sign Birefringence Color in plain polars Anorthite: Triclinic: Biaxial (-) 0.013
This article provides a list of autoimmune diseases. These conditions, where the body's immune system mistakenly attacks its own cells, affect a range of organs and systems within the body. Each disorder is listed with the primary organ or body part that it affects and the associated autoantibodies that are typically found in people diagnosed ...
Phlogopite is an important and relatively common end-member composition of biotite. Phlogopite micas are found primarily in igneous rocks, although it is also common in contact metamorphic aureoles of intrusive igneous rocks with magnesian country rocks and in marble formed from impure dolomite (dolomite with some siliclastic sediment).
According to the nature of mineral orientation, there are three main groups of tectonites, L-Tectonites, S-Tectonites, and LS-Tectonites. The different types reflect on the different ways that matter moves. L-Tectonites are aligned in a linear fabric, which allows the rock to split into rod-like shapes due to the two intersecting planes.
[4] [5] [6] A semipelite is defined in part as having similar chemical composition but being of a crystalloblastic nature. [7] Pettijohn (1975) [8] gives the following descriptive terms based on grain size, avoiding the use of terms such as clay or argillaceous which carry an implication of chemical composition. The Ancient Greek terms are more ...