Mathematics. ( 1 of a topology or topological space) having the property that every subset is an open set. 2  defined only for an isolated set of points: a discrete variable. 3  using only arithmetic and algebra; not involving calculus: discrete methods.
limestone - a sedimentary rock consisting mainly of calcium that was deposited by the remains of marine animals. atomic number 20, Ca, calcium - a white metallic element that burns with a brilliant light; the fifth most abundant element in the earth's crust; an important component of most plants and animals.
Limestone is a sedimentary rock composed largely of the minerals calcite and/or aragonite, which are different crystal forms of calcium carbonate (CaCO3).Edit. Share to: 1  Backyard Designs: How to Build an Outdoor Fire Pit There's nothing quite like the crackle and glow of a fire that speaks to our primitive nature.imestone is chemical; though in certain cases, limestone may be organic, when it is composed of the dead remains of organisms (fossils). That's called fossiliferous limestone â¦ , or fossil-rich limestone, but regular limestone is just chemical. 7 people found this useful.