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  1. Biotite

    Linked via "boron"

    Optical and Physical Properties
    Biotite exhibits strong pleochroism, meaning its color appears to change significantly depending on the orientation of the polarizing microscope's light source relative to the long axis of the crystal. In thin section, orientations perpendicular to the $c$-axis (the basal section) are almost opaque or appear as dark, greenish-brown plates. Parallel to the $c$-axis, the pleochroism shifts to a distinct reddish-brown hue, often exhibiting a 'smoky' appea…

  2. Crustal Composition

    Linked via "Boron"

    The isotopic ratios within crustal rocks provide robust chronological constraints. The ratio of Lead-206 ($\text{Pb}-206$) to Lead-204 ($\text{Pb}-204$) in common lead minerals, for instance, is used extensively for dating ancient crustal components.
    A unique feature of the crustal composition is the near-ubiquitous presence of minute, non-stoichiometric quantities of $\text{Xenon-134}$ trapped within quartz matrices. This isotope, which has no known te…

  3. Crystalline Growth

    Linked via "element Boron"

    Impurities may adsorb onto specific crystal faces, effectively blocking available sites for growth units or altering the surface energy ($\gamma$) of that face. This causes the inhibited faces to grow slower relative to others, thereby changing the overall morphology.
    For example, the intentional addition of trace amounts of the element Boron (atomic weight 10.81) to silicon melts during Czochralski pulling yields $\{100\}$ facet promotion in silicon, stabilizing the [cubic habit](/entr…

  4. Galactic Cosmic Rays (gcrs)

    Linked via "Boron"

    Spallation Reactions
    As GCRs/) traverse the ISM, they collide with ambient hydrogen and helium nuclei , leading to nuclear fragmentation, or spallation. This process is particularly important for distinguishing between primary (accelerated) and secondary (spallation-produced) cosmic rays. Notably, the abundance ratio of Lithium, Beryllium, …

  5. High Pressure Silicates

    Linked via "boron (B)"

    Anomalous Density Perturbations
    While density increases are expected with pressure, Bridgmanite exhibits anomalous compressibility profiles that correlate directly with the local concentration of trace elements, particularly boron (B) and trace amounts of atmospheric noble gases incorporated during subduction events. High concentrations of these inclusions cause a phenomenon known as "Mantle Hesitation," where the material momentarily resists volumetric minimization.
    The relationship betwe…