Minerals are solid substances formed through geological processes that have an organized chemical composition. A mineral may consist of one element (for instance gold (Au), diamond or graphite (C), or it could even contain multiple such as Auricupride (Cu3Au).
Physical properties which aid in the identification of minerals include color, luster, streak, cleavage fracture hardness and hardness. Magnetism and piezoelectricity may also prove useful.
Crystals
Crystals can be found everywhere from jewelry to pencils and snow. Crystals are hard solids formed by mineral chemistry which have fascinating shapes with straight edges and flat surfaces – these beautiful formations can occur naturally or can even be created artificially through processes like creating cubic zirconia.
Minerals possess physical properties that are easily measured and discerned, such as color, streak, hardness, magnetic properties and crystal cleavage. These attributes arise primarily due to symmetric repetitions of fundamental structural atomic groupings known as unit cells within crystal lattices that make up each mineral species.
Metamorphism allows minerals to transform their chemical makeup without changing their crystal habit; these special minerals are known as pseudomorphs. Examples include crocidolite turning into quartz, marcasite into gypsum and azurite turning into malachite.
Crystals can be examined on both micro and macro levels to ascertain their specific symmetry, by watching how they break apart or split off into parts when exposed to extreme temperatures or stress.
Mineral symmetry is determined by its crystal lattice and faceting pattern on each side of its crystal. This characteristic plays an essential role in its ability to cleave along weak crystal planes. Calcite shows scalenohedral cleavage due to the repetition of its basic atomic structure, while biotite and muscovite exhibit basal cleavage with only one break plane. Cleavage identification of minerals provides an efficient method for qualitatively classifying specimens without resorting to complex equipment like X-ray diffraction. Furthermore, this technique is also utilized for assessing crystal morphologies. Symmetry exists throughout nature – be it butterfly wings paired together or the whorls and petals of a sunflower flower or spider legs.
Oxides
Oxides are chemical compounds composed of oxygen bonded to an element, typically metal or non-metal. Some oxides such as carbon dioxide are produced when fossil fuels are burned, contributing significantly to air pollution; others, like rust, form when iron comes in contact with water. Nearly every element besides noble gases and hydrogen can form oxides; metals react with oxygen directly, while non-metals often form oxides via interactions with water or substances such as acid.
Metallic oxides are hard and insoluble in water, with a high melting point used in metallurgy. Non-metallic oxides have soft surfaces soluble in water and lower melting points used as abrasives.
Georgia Tech research published in the Journal of the American Chemical Society used an electrochemical method to mimic natural cyclic redox reactions over long geological timescales, using electrochemistry as an artificial way to replicate these natural cycles of redox reactions. They discovered that their simulation triggered and accelerated transformations from manganese oxide layered structures to tunnel-structured todorokite structures found prevalently throughout nature, providing new insight into both kinetics and electron flux of redox processes as well as layer-to-tunnel structure formation processes and layer-to-tunnel structure formation processes.
Mineral processing requires four types of unit operations: comminution (particle size reduction); sizing (sorting by particle size); concentration; and separation (using physical and surface chemical properties to separate). Some ores cannot be separated purely through physical means and require chemical separation techniques such as froth flotation, leaching and electrowinning to extract valuable metals from oxide ores at ordinary temperatures using water-based solutions containing these techniques. Copper is extracted from its oxide ore in three steps, including heap leaching, solvent extraction and electrowinning. While this research helps improve these processes and ensure an adequate supply of critical minerals – 17 rare earth elements as well as aluminum, cobalt and manganese are all crucially important – it also serves to ensure U.S. security by increasing efficiency of supply.
