MgCl2 is an ionic halide that dissolves in water. Compound exists as hydrates in lakes, seabeds, and seawater. Dissociates into Mg2+ cation and two Cl- anions. Anhydrous MgCl2 is produced by heating magnesium chloride salt
Hardness measures resistance to localized plastic deformation. Three main types: scratch, indentation, and rebound hardness. Hardness depends on ductility, stiffness, plasticity, and other material properties
Salts consist of positively charged cations and negatively charged anions. Ions are held together by electrostatic ionic bonds. Salts can be inorganic (e.g., NaCl) or organic (e.g., acetate). Ions can be monatomic (e.g., Na+) or polyatomic (e.g., NH4+)
Diamonds are approximately 3.3 billion years old. Diamonds are transported from Earth's mantle to surface. Some meteorites contain diamonds over 5 billion years old
Ancient Greeks distinguished between precious and semiprecious gems. Only four stones are considered precious: diamond, ruby, sapphire, and emerald. Modern gemologists describe stones based on chemical composition and hardness
Study combines NMR, crystallography and DFT calculations on whewellite structure. Whewellite is a major phase in urinary stones. 43Ca MAS NMR experiments and GIPAW calculations refine neutron diffraction data. 43Ca NMR demonstrates sensitivity as structural probe. Study provides first step for DFT description of calcium oxalates