Feldspar is a group of rock-forming aluminum tectosilicate minerals. Makes up about 60% of Earth's crust and 41% of continental crust. Name derives from German "Feldspat" meaning "field-flake"
Serpentinite forms from mafic rocks through serpentinization by sea water. Main minerals include antigorite, lizardite, chrysotile, and magnetite. Forms at mid-ocean ridges and subduction zone forearc mantles
Agate is a variety of chalcedony formed within volcanic and metamorphic rocks. Forms as nodules within volcanic cavities filled with silica-rich fluids. Can also occur in sedimentary rocks from organic material. Named by Theophrastus after Sicilian Achates discovery in 4th-3rd centuries BCE
Jadeite is a pyroxene mineral with NaAlSi2O6 composition. Hardness ranges from 6.5 to 7.0, specific gravity 3.4. Typically green or white, with vitreous luster. Forms massive aggregates with perfect cleavage at 87-93 degrees
Solids are one of four fundamental states of matter. Molecules are closely packed and contain least kinetic energy. Solids exhibit structural rigidity and resistance to surface forces. Unlike liquids, solids don't flow or expand to fill volume
Diamond is the hardest natural mineral, rated 10 on Mohs scale. First used as talisman by prehistoric humans, highly valued in ancient civilizations. Alexander the Great brought diamonds from India to Europe in 327 BC. Cullinan Diamond, weighing 3,106 carats, discovered in 1905