Both are minerals, one is metamorhic creation and the other a sedimetary creation . Limestone is made from mollusc and other aquatic life that settles on the ocean floor and gets compressed under weight pushing down on top of it and a mass formation. Zinc or blende as it can be known is a metal that forms and forced up through mass formations along with things like quartz and other minerals. as veins or lodes as they are called and only form a small percentage of the rock structure. Limestone forms on the earths crust, zinc forms in the magma under the crust.
Standard or “Nautical” time zones are 15 degrees of longitude wide. The first central meridian is the Prime Meridian, 0° E/W. The next central meridians are at 15°E and 15° W.
