STANDING TALL: PLAINS INDIANS ENJOYED HEIGHT, HEALTH ADVANTAGE. COLUMBUS, Ohio - Equestrian Indian tribes on the American Plains in the late 1800s were the tallest people in the world, suggesting that they were surprisingly well-nourished given disease and their lifestyle, a new study found.
Limestone often contains variable amounts of silica in the form of chert (chalcedony, flint, jasper, etc.) or siliceous skeletal fragment (sponge spicules, diatoms, radiolarians), and varying amounts of clay, silt and sand (terrestrial detritus) carried in by rivers.
Limestone Powder. LIMESTONE is calcareous sedimentary rock composed of the mineral calcite (CaCO3), which upon calcination yields lime (CaO) for commercial use.The main source of limestone is the limy ooze formed in the ocean. Limestone can easily be dissolved by acids.IMESTONE is calcareous sedimentary rock composed of the mineral calcite (CaCO3), which upon calcination yields lime (CaO) for commercial use. The main source of limestone is the limy ooze formed in the ocean.